Refining of Edible oils

Babitha iyer

2012-07-23T22:08:00.000-07:00

Taarak Mehta Ka Ooltah Chashmah

2012-07-23T22:03:00.003-07:00

Taarak Mehta Ka Ooltah Chashmah

Format	Situational comedy
Created by	Sab TV Team Neela Telefilms
Written by	Raju Odedra Rajan Upadhyay
Directed by	Harshad Joshi
Starring	See Below
Opening theme	"Taarak Mehta Ka Ooltah Chashmah" by Shailendra Barve
Country of origin	India
Language(s)	Hindi
No. of seasons	4
No. of episodes	926 as on July 27, 2012
Production
Producer(s)	Neela Asit Modi Asit Kumar Modi
Running time	Approx. 20 minutes
Broadcast
Original channel	SAB TV
Picture format	480i (SDTV)
Original run	July 28, 2008 – Present
External links
Website

Taarak Mehta Ka Ooltah Chashmah is an Indian sitcom that airs on SAB TV. The show first aired on July 28, 2008 and is produced by Neela Telefilms. The show and its title are based on the column Duniya Ne Oondha Chashmah (Gujarati: દુનિયાને ઉંધા ચશ્મા) which loosely translates to "Seeing The World Through Upside-Down glasses" written by columnist and journalist Taarak Mehta for the Gujarati weeklymagazine Chitralekha.^[1]

In August 2010, the show beat Colors TV's popular serial Balika Vadhu.^[2] It has often been noted for its frequent references to issues of social importance in the country and its positive approach towards the problems faced by the society.^[3] Lauded performances by its lead and supporting actors alike have also contributed in making the show a success.^[4] On June 22, 2012, the show completed 900 episodes thus becoming the longest running daily comedy show of all time on indian television.^{[citation needed]}

The serial's producer Asit Modi spend lot of money on the construction of sets.^[5] The outer set is made of wooden planks and the inner sets are located at different studios in the Dadasaheb Phalke Filmcity.^[5] In March 2012, the set was renovated.^[6]

[hide]

[edit]Plot

The serial is based on the happenings of Gokuldham Society and the day-to-day life of its members. The Gokuldham society is a mix of India's social fabric which is mentioned in the sitcom to be present in Powder Gali, Goregaon East, Mumbai. In the society live Gujaratis, Marathis, Punjabis, Biharis, South Indians, Bengalis, Parsis and Muslims in harmony.

All the people of the society are good friends and they share a great sense of camaraderie among each other. Gokuldham Society celebrates all the festivals together, with pomp and vigour. They do quarrel with each other at times, but soon enough patch things up. Whenever there are any mishaps, the entire society comes together and tackles the problem and helps each other. The society members live together like a family. Gokuldham Society depicts a miniature India as it shows "Unity In Diversity".

[edit]Gada Family

The story mainly revolves around Jethalal Champaklal Gada and his family. Gada family is Kutchi-Gujarati Jain. Jethalal is a successful businessman and runs an electronic store, "Gada Electronics", in Andheri, Mumbai. He has only studied until class 10 and cannot speakEnglish. This serial captures the drama of his day to day life and his interactions with the people of Gokuldham society. His wife, Daya Jethalal Gada, is an uneducated, family oriented woman, who has studied till class 7. She is always ready to dance the "Garba"(gujrati folk dance) and people call her "Garba Queen". She is from Ahmedabad. She is shown to be always on the phone with her mother, who finds new and funny names for Jethalal. She calls Jethalal as "Tapu Ke Papa" as she, like many Indian housewife, think it is sin to take the husband's name. Jethalal often scolds her. Despite this, there is love and unity between the two main protagonists of this show.

They have a son Tipendra Jethalal Gada(Tappu), who is smart but very naughty. Tappu is the leader of society's children's brigade known as "Tappu Sena". Champaklal Jayantilal Gada, father of Jethalal is a very kind man and an ideal grandfather in his late sixties. He is an ardent gandhian. He is very religious and the entire society respects him. He often scolds Jethalal when he disrespects Daya. He looks like his father Late Jayantilal Girdharlal Gada.

A prominent non-resident of Gokuldham society is Daya's brother, Sundarlal(Sundar), referred to by Daya as "Sundar veera". He is very affectionate towards his sister and nephew, but creates problems for Jethalal. A common situation involves Sundar travelling all the way from Ahmedabad to Mumbai in an air conditioned taxi and asking Jethalal to pay the fare, giving excuses that he doesn't have enough cash while promising to pay back the money soon, which he never does. Jethalal gets irritated by him and refers to Sundar as "Panoti" meaning "Unlucky person".

[edit]Mehta Family

Taarak Mehta is a writer by profession and is the narrator of the show as well as Jethalal's best friend in the Society. Whenever Jethalal has a problem, Taarak Mehta acts as his "fire brigade". Taarak Mehta is portrayed to be a modern man who, however, does not forget his traditional values. He helps everybody in society. His wife, Anjali Taarak Mehta, is a dietician and feeds her husband only with diet-rich foods such as freshly prepared "bitter-gourd juice and khichdi". She is a good friend of all ladies of society.

[edit]Bhide Family

The Marathi family, the Bhides, consists of Aatmaram Tukaram Bhide, a teacher, who is forever nostalgic about "good old times", his wife Madhavi Aatmaram Bhide, and their daughter Sonu Aatmaram Bhide. Aatmaram is also the secretary of the society and often says himself as "ekmev secretary" meaning "one and only secretary". He has a love-hate relationship with Jethalal and his family. He had a scooter which never starts which he later, after much persuasion for all the members of the society, decided to sell off. He is usually shown to be complaining about Tappu's mischief. He always want to maintain discipline in society but no one listens to him. His wife Madhavi is a home-based businesswoman who sells "achaar" meaning "pickle" and "papad". She often gets tired of her husband's behaviour. His daughter Sonu is a intelligent girl and is Tappu's best friend. One of Aatmaram's worries in life is that Sonu would fall in love with Tappu.

[edit]Iyer Family

The Iyer family consists of Krishnan Subrahmaniam Iyer and his wife Babita Krishnan Iyer. Krishnan Iyer is a South Indian hailing from Chennai who is a well-known scientist and his wife Babita isBengali from Kolkata. While Krishnan Iyer's complexion is dark, Babita is fair. Jethalal has a innocent crush on Babita. Jethalal often flirts with Babita ji, but every time his efforts come to naught because of her husband. So, he always looks for a reason to settle scores and get back at Jethalal Gada. Babita is a beautiful, modern woman. She thinks Jethalal and Daya as her good friends and opposes her husband whenever he fights with Jethalal.

[edit]Sodhi Family

The Sodhis are a pair of Punjabi husband and Parsi wife having the same name. Theirs is a love marriage. Roshan Singh Ajit Singh Sodhi, is a garage owner and is a happy-go-lucky person who gets aggressive with those who mess with him or any of the society members. He is always ready for a party and the subsequent drinking binge. Mrs. Roshan Kaur Roshan Singh Sodhi is a housewife with a pleasant personality. She loves her husband and son. She doesn't like her husband's habit of drinking, which seems to be the only fly in the ointment of their happy married life. They have a son, Gurucharan Singh Roshan Singh Sodhi(Gogi), who is the youngest child in the Tappu Sena.

[edit]Hathi Family

The Bihari family of Hathis include Dr Hansraj Hathi, a doctor who is morbidly obese, who is fond of eating. He often comments as "Sahi baat hai" meaning "that's right". His wife Komal Hansraj Hathi, who is also morbidly obese, is a modern woman and a housewife who tries to keep a check on her husband's and son Goli's eating habits. Goli Hansraj Hathi is like his father who is always eating food. He is very naughty and often scolded by the adults.

[edit]Other members

Another funny character in the show is Patrakar Popatlal, a journalist from Toofan Express(a parody of the real-life newspaper Indian Express) who also resides in the society. He is a North Indianand hails from Bhopal. He is very cynical and demands everything to be cancelled, with the tag lines "cancel kardo" and "duniya hila doonga". He always carries an umbrella with him. Born on February 29, he always tries to marry but in vain.

In the evenings, all the men in the society meet after dinner at the shop nearby the society for their regular glass of soda. The shop is run by Abdul, a simple Muslim person who is like a member of the society. A news reporter named Rita Shrivastav is also the member of the society, who always helps the ladies and children. She works as a correspondent for the news channel "Kal Tak"(parody of a real-life Hindi news channel named Aaj Tak). There is always a fight between Popatlal (print journalist) and Rita (television news reporter), as they both consider their media as superior to the other. There is another boy named Pinku Diwan, who lives alone and his parents are never shown in the show and are assumed to be working abroad.

Natwarlal Prabhashankar Udaywala (Nattu Kaka) is an employee in Jethalal's electronics shop. He is in his sixties but consideres himself as young and speaks some English. He constantly demands that his salary be increased. Whenever Jethalal scolds him, he pretends to have hearing problem and says, "aapne mujhse kucch kahaa?"(Did you say something to me) . Bageshwar Dadukh Udaywala(Baga) is Nattu Kaka's nephew and Jethalal's employee. He is funny and creates problems in Jethalal's life. Baga always says, "jaisi jiski soch"(Each to his way of thinking). The uncle and nephew both have a great bonding with each other.

[edit]Cast and Characters

Actor	Character
Gada Family
Dilip Joshi	Jethalal Champaklal Gada
Disha Vakani	Daya Jethalal Gada
Bhavya Gandhi	Tipendra Jethalal Gada / Tapu
Amit Bhatt	Champaklal Jayantilal Gada
Amit Bhatt	Jayantilal Girdharlal Gada
Mehta Family
Shailesh Lodha	Taarak Mehta
Neha K Mehta^[7]	Anjali Taarak Mehta
Bhide Family
Mandar Chandwadkar	Aatmaram Tukaram Bhide
Sonalika Joshi	Madhavi Aatmaram Bhide
Jheel Mehta	Sonu Aatmaram Bhide
Sodhi Family
Gurucharan Singh	Roshan Singh Harjeet Singh Sodhi
Jennifer Mistry Bansiwal	Roshan Kaur Roshan Singh Sodhi
Samay Shah	Gurucharan Roshan Singh Sodhi / Gogi
Iyer Family
Tanuj Mahashabde	Krishnan Subramaniam Iyer / Iyer
Moonmoon Dutta	Babita Krishnan Iyer
Hathi Family
Nirmal Soni / Azad Kavi	Dr. Hansraj Hathi
Ambika Ranjankar	Komal Hansraj Hathi
Kush Shah	Goli Hansraj Hathi / Golya
Others
Ghanashyam Nayak	Natwarlal Prabhashankar Udaywala / Nattu Kaka
Tanmay Vekaria	Bageshwar Dadukh Udaywala / Baga
Mayur Vakani	Sundarlal / Sundar
Shyam Pathak	Patrakar Popatlal Pandey / Popatlal
Priya Ahuja / Nidhi	Rita Shrivastav / Rita Reporter
Sharad Sankla	Abdul
Tarun Uppal	Pinku Diwan
Dayashankar Pandey	Inspector Chalu Pandey
Anil Yadav	Matka King Mohanlal
Kary Irwin	Kary
Sanjay Wadekar	Chotu Chaiwala

DILIP JOSHI (JETHALAL CHAMPAKLAL GADA

2012-07-23T22:01:00.003-07:00

Dilip Joshi(born 26 May 1968) is an Indian film and television actor. He has appeared in a number of serials as well as films. He acts mostly incomedy and is currently playing the role of Jethalal Champaklal Gada^[1] in Taarak Mehta Ka Ooltah Chashmah.

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[edit]Career

Joshi has appeared in several Gujarati dramas, one of them being Bapu Tame Kamaal Kari with Sumeet Raghavan and Amit Mistry, the trio known for their television serial Shubh Mangal Savadhan. Joshi starred in the show Kya Baat Hai, in which he played a South Indian accountant. He also appeared in the film Maine Pyaar Kiya, Hum Aapke Hain Kaun..! etc.

He plays the role of Jethalal Gada in Taarak Mehta Ka Ooltah Chashmah. Notable among his tele-serials in Hindi are Kabhi Yeh Kabhi Woh, Hum Sub Ek Hain, Shubh Mangal Savdhan, Yeh Duniya Hai Rangeen, Meri Biwi Wonderful and Taarak Mehta Ka Ooltah Chashmah. He appeared in the children's comedy serial Agadam Bagdam Tigdam as Uncle Tappu, as well as in the 2009 films Dhoondte Reh Jaaoge and Ashutosh Gowarikar'sWhat's Your Raashee?.

[edit]Filmography

[edit]Television

Dilip Joshi with Abhishek Bachchan on the sets of Taarak Mehta Ka Ooltah Chashmah

Galatnaama
Kabhi Yeh Kabhi Woh as Vasu
Zara Hatke as Sonu
Gopaljee as Titto
Kya Baat Hai as Rangaswamy
Daal Mein Kala as Bharat
Sewalal Mewawala (1999) as Mr Sewalal Mewa Jee
Kora Kagaz
Shubh Mangal Saavdhan as Dilip
Hum Sab Ek Hain (1998–2001) as Sohan Khachroo
Yeh Duniya Hai Rangeen (2000–2001) as Balkrishna Namudari
Meri Biwi Wonderful (2002–2003) as Raj
Aaj Ke Shriman Shrimati
Kudkudiya House No 43
Bhagwan Bachaye Inko as Gopi
Do Aur Do Paanch as Rahul
CID Special Bureau as Bob
Agadam Bagdam Tigdam (2007) as Uncle Tappu
Taarak Mehta Ka Ooltah Chashmah (2008–present) as Jethalal Gada

[edit]Films

Year	Film	Role
1989	Maine Pyar Kiya	Ramu
1992	Hun Hunshi Hunshilal	Hunshilal
1994	Hum Aapke Hain Koun..!	Bhola Prasad
1996	Yash	Gopi
2000	Phir Bhi Dil Hai Hindustani	Sapney
2000	Khiladi 420	Arora
2001	One 2 Ka 4	Champak
2002	Humraaz	Guest Appearance
2002	Dil Hai Tumhaara	Factory CEO
2008	Firaaq	Deven
2008	Don Muthu Swami	Fikarchand
2009	Dhoondte Reh Jaaoge	Mama Nautanki
2009	What's Your Raashee?	Jitubhai

[edit]Awards

[edit]Indian Telly Awards

2009: Best Actor in Comic Role(Male); Taarak Mehta Ka Ooltah Chashmah

2010: Most Popular Actor in Comic Role(Male); Taarak Mehta Ka Ooltah Chashmah

2012: Most Popular Actor in a Comic Role(Male); Taarak Mehta Ka Ooltah Chashmah

[edit]Zee Gold Awards

2010: Best Actor in Comic Role(Male); Taarak Mehta Ka Ooltah Chashmah

2011: Best Actor in Comic Role (Male); Taarak Mehta Ka Ooltah Chashmah

[edit]Lions Gold Awards

2010: Lions Favorite Actor in a Comic Role(Male); Taarak Mehta Ka Ooltah Chashmah

[edit]The Global Indian Film and Television Honours

2011: Best Actor in Comic Role; Taarak Mehta Ka Ooltah Chashmah

[edit]BIG Star Entertainment Awards

2011: BIG Star Most Entertaining Television Television Actor(Male); Taarak Mehta Ka Ooltah Chashmah

Twenty for Twenty: Vegetarian Edition

2012-07-22T22:35:00.003-07:00

The Ingredients

To make the 20 recipes below, stock up on these 20 ingredients (and be sure your pantry includes the essential ingredients listed on the right).

1. Tahini
2. Lemons
3. Limes
4. Canned garbanzo beans
5. Canned black beans
6. Fresh ginger root
7. Tomatoes
8. Tomato puree
9. Celery
10. Raw jalapeno peppers
11. Spinach
12. Onions (white, red, green)
13. Garlic
14. Bell peppers (green, red, yellow)
15. Tofu
16. Lentils
17. White rice
18. Eggs
19. Parmesan
20. Cheddar cheese

The Recipes

With the above 20 ingredients, you can make these 20 delicious and distinct vegetarian meals--everything from lentil stew to tofu burgers.

Hearty Vegetable Lasagna

2012-07-22T22:34:00.002-07:00

Ingredients

1 (16 ounce) package lasagna noodles
1 pound fresh mushrooms, sliced
3/4 cup chopped green bell pepper
3/4 cup chopped onion
3 cloves garlic, minced
2 tablespoons vegetable oil
2 (26 ounce) jars pasta sauce
1 teaspoon dried basil
1 (15 ounce) container part-skim ricotta cheese
4 cups shredded mozzarella cheese
2 eggs
1/2 cup grated Parmesan cheese

Directions

Cook the lasagna noodles in a large pot of boiling water for 10 minutes, or until al dente. Rinse with cold water, and drain.
In a large saucepan, cook and stir mushrooms, green peppers, onion, and garlic in oil. Stir in pasta sauce and basil; bring to a boil. Reduce heat, and simmer 15 minutes.
Mix together ricotta, 2 cups mozzarella cheese, and eggs.
Preheat oven to 350 degrees F (175 degrees C). Spread 1 cup tomato sauce into the bottom of a greased 9x13 inch baking dish. Layer 1/2 each, lasagna noodles, ricotta mix, sauce, and Parmesan cheese. Repeat layering, and top with remaining 2 cups mozzarella cheese.
Bake, uncovered, for 40 minutes. Let stand 15 minutes before serving.

Nutritional Information

Amount Per Serving Calories: 462 | Total Fat: 19.5g | Cholesterol: 81mg

What is Oil Refinery and Edible Oil Refinery?

2012-07-22T22:33:00.002-07:00

What is Oil Refinery and Edible Oil Refinery?

When talking about refinery, we need to be able to differentiate and identify an oil refinery from the edible oil refinery. Basically, the oil refinery (or petroleum refinery) is an industrial process plant where crude oil (from crude petroleum) is processed and refined into more useful petroleum products, such as gasoline, diesel fuel, asphalt base, heating oil, kerosene, and liquefied petroleum gas. This is the type of refinery mentioned in the 13 Days: Pythagoras Conspiracy Novel. An edible oil plant in the other hand, is almost similar to the earlier refinery accept it processes edible oil and involves the removal of fatty acid and a few more unwanted impurities. The edible oils are obtained from the likes of palm oil, soya bean oil, canola oil, corn oil, rape seed oil and others. In other words, the oil refinery process oil that cannot be consumed by human being while the edible oil refinery process oil that is edible (can be consumed by human beings).

I have no direct involvement in the oil refinery. However, I was a process engineer in an edible refinery plant before for quite some time. I had a really good taste of experience working in the refinery plant before. I strongly believe that if a chemical engineering student or a new chemical engineer wants to gain experience, he or she should work in a refinery. This is mainly because they will learn and apply all that they have learn in chemical engineering.

Edible Oil Refinery

Edible oil originates from crude oil such as crude palm oil (CPO), crude soya bean oil (CSBO), crude rape seed oil (CRSO), crude coconut oil (CCO) and so on. Edible oils have very high content of free fatty acids (FFA) and needs to be refined before using as cooking oil. However, the refinery process isn't only limited to remove FFA, it also removes the undesired components such as moisture, color and odour which may trigger negative impact on the final taste, odour and appearance of the oil product. The resultant oil is thinner without fatty acids, colorless and odorless.

It is imperative to note that the edible oil refinery can be divided into 2 primary types namely, chemical refining and physical refining. This time, I'll explain about the chemical refining plant.

Chemical Refining Plant

Chemical refining plant involve neutralization of crude oil by removing fatty acids. This is always referred to as chemical refining or sometimes Neutralizing process and its plant referred as Neutralizing Plant (NP). In this process the oil is neutralized in the neutralizer to remove the fatty acids by mixing with caustic soda (sodium hydroxide). Oil is heated up to roughly 60oC by and oil is stirred by stirrer. The fatty acids are settled at the bottom as alkali soaps which is called soapstock from where it is taken out into soap tank .

Typical Neutralizing Plant. Image credited to Oiltek Sdn Bhd, a Malaysian company that manufactures edible oil equipments. Click on the photo to enlarge it.

Removal of impurities and color

Neutralized oil is passed through the second vessel called bleacher where color of oil is removed by bleaching process with the help of chemicals such as carbon black andbleaching clay. Oil is usually heated up to 110oC. Stirring is also carried on. Bleaching process is done under vacuum. Bleached oil then goes to filtration process where bleaching clay and chemicals are removed and cleaned.

Removal of unpleasant smell

Bleached oil is then passed through deodorizer where oil is heated above 110C and then live steam clean is used to the oil from the bottom steam nozzles. The temperature of oil is raised up to 200 to 220C through thermic fluid coils. Entire process is done under high vacuum. Thus smell is removed from the oil in the deodorizer. Then it goes to cooler where cold water circulating coils take away heat and oil is cooled.

Final Filtration

Final filtration is performed after cooling down the oil. This operation is carried out in a micro filter closet or filter bag/filter cartridge which makes the final edible oil termed as refined edible oil. This final filtration process is designed for more effective filtration and best quality of final refined edible oil. There are certain refineries that adoptedHazard Analysis Critical Control Point (HACCP) to completely ensure that the oil is free and safe to be consumed.

This is a typical physical refinery plant. The image is also credited to Oiltek. Click the image to enlarge it.

In the next post, I'll describe more about the Physical Refinery. This is where I gained the most of my hands on chemical engineering experiences. This is where I learned more about important unit operations such as heat exchanger, cooling tower, deodoriser, pack coloumn etc.

.......................................................................

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Vegetarian Korma

2012-07-22T22:32:00.002-07:00

Ingredients

1 1/2 tablespoons vegetable oil
1 small onion, diced
1 teaspoon minced fresh ginger root
4 cloves garlic, minced
2 potatoes, cubed
4 carrots, cubed
1 fresh jalapeno pepper, seeded and sliced
3 tablespoons ground unsalted cashews
1 (4 ounce) can tomato sauce
2 teaspoons salt
1 1/2 tablespoons curry powder
1 cup frozen green peas
1/2 green bell pepper, chopped
1/2 red bell pepper, chopped
1 cup heavy cream
1 bunch fresh cilantro for garnish

Directions

Heat the oil in a skillet over medium heat. Stir in the onion, and cook until tender. Mix in ginger and garlic, and continue cooking 1 minute. Mix potatoes, carrots, jalapeno, cashews, and tomato sauce. Season with salt and curry powder. Cook and stir 10 minutes, or until potatoes are tender.
Stir peas, green bell pepper, red bell pepper, and cream into the skillet. Reduce heat to low, cover, and simmer 10 minutes. Garnish with cilantro to serve.

Nutritional Information

Amount Per Serving Calories: 462 | Total Fat: 31.1g | Cholesterol: 82mg

List of vegetable oils

2012-07-22T22:28:00.002-07:00

Vegetable oils are triglycerides extracted from plants. Such oils have been part of human culture for millennia.^[1] Edible vegetable oils are used in food, both in cookingand as supplements. Many oils, edible and otherwise, are burned as fuel, such as in oil lamps and as a substitute for petroleum-based fuels. Some of the many other uses include wood finishing, oil painting, and skin care.

There are three principal methods for extracting vegetable oils. The relevant part of the plant may be placed under pressure to extract the oil, giving an expressed oil. Oils may also be extracted from plants by dissolving parts of plants in water or another solvent. The solution may be separated from the plant material and concentrated, giving an extracted or leached oil. The mixture may also be separated by distilling the oil away from the plant material. Oils extracted by this latter method are called essential oils. Essential oils often have different properties and uses than pressed or leached vegetable oils. Macerated oils are made by infusing parts of plants in a base oil, a process called liquid-liquid extraction.

The term "vegetable oil" can be narrowly defined as referring only to substances that are liquid at room temperature,^[2] or broadly defined without regard to a substance's state of matter at a given temperature.^[3] For this reason, some of the entries on this list do not qualify as vegetable oils according to all understandings of the term.

Although most plants contain some oil, only the oil from certain major oil crops^[4] complemented by a few dozen minor oil crops^[5] is widely used and traded. These oils are one of several types of plant oils.

Vegetable oils can be classified in several ways, for example:

By source: most, but not all vegetable oils are extracted from the fruits or seeds of plants, and the oils may be classified by grouping oils from similar plants, such as "nut oils".
By use: as described above, oils from plants are used in cooking, for fuel, for cosmetics, for medical purposes, and for other industrial purposes.

The vegetable oils are grouped below in common classes of use.

Major oils

Sunflowers, the seeds of which are the source of sunflower oil.

These oils make up a significant fraction of worldwide edible oil production. All are also used as fuel oils.

Coconut oil, a cooking oil, with medical and industrial applications as well. Extracted from the kernel or meat of the fruit of the coconut palm. Common in the tropics, and unusual in composition, with medium chain fatty acids dominant.^[6]
Corn oil, one of the principal oils sold as salad and cooking oil.^[7]
Cottonseed oil, used as a salad and cooking oil, both domestically and industrially.^[8]
Olive oil, used in cooking, cosmetics, soaps, and as a fuel for traditional oil lamps.^[9]
Palm oil, the most widely produced tropical oil.^[10] Popular in West African and Brazilian cuisine.^[11] Also used to make biofuel.^[12]
Peanut oil (Ground nut oil), a clear oil with some applications as a salad dressing, and, due to its high smoke point, especially used for frying.^[13]
Rapeseed oil, including Canola oil, one of the most widely used cooking oils.^[14]
Safflower oil, until the 1960s used in the paint industry, now mostly as a cooking oil.^[15]
Sesame oil, cold pressed as light cooking oil, hot pressed for a darker and stronger flavor.^[16]
Soybean oil, produced as a byproduct of processing soy meal.^[17]
Sunflower oil, a common cooking oil, also used to make biodiesel.^[18]

[edit]Nut oils

Hazelnuts from the Common Hazel, used to make Hazelnut oil.

Nut oils are generally used in cooking, for their flavor. Most are quite costly, because of the difficulty of extracting the oil.

Almond oil, used as an edible oil, but primarily in the manufacture of cosmetics.^[19]
Beech nut oil, from Fagus sylvatica nuts, is a well-regarded edible oil in Europe, used for salads and cooking.^[20]
Cashew oil, somewhat comparable to olive oil. May have value for fighting dental cavities.^[21]
Hazelnut oil, mainly used for its flavor. Also used in skin care, because of its slight astringent nature.^[22]
Macadamia oil, with a mild nutty flavor and a high smoke point.^[23]
Mongongo nut oil (or manketti oil), from the seeds of the Schinziophyton rautanenii, a tree which grows in South Africa. High in vitamin E. Also used in skin care.^[24]
Pecan oil, valued as a food oil, but requiring fresh pecans for good quality oil.^[25]
Pine nut oil, sold as a gourmet cooking oil,^[26]^[27] and of potential medicinal interest as an appetite suppressant.^[28]
Pistachio oil, a strongly flavored oil with a distinctive green color.^[23]
Walnut oil, used for its flavor,^[23] also used by Renaissance painters in oil paints.^[29]^[30]

[edit]Citrus oils

A number of citrus plants yield pressed oils. Some, such as lemon and orange oil, are used as essential oils, which is uncommon for pressed oils. The seeds of many if not most members of the citrus family yield usable oils.^[31]^[32]^[33]

Grapefruit seed oil, extracted from the seeds of grapefruit (Citrus × paradisi). Grapefruit seed oil was extracted experimentally in 1930 and was shown to be suitable for making soap.^[34]
Lemon oil, similar in fragrance to the fruit. One of a small number of cold pressed essential oils.^[35] Used as a flavoring agent^[36] and in aromatherapy.^[37]
Orange oil, like lemon oil, cold pressed rather than distilled.^[38] Consists of 90% d-Limonene. Used as a fragrance, in cleaning products and in flavoring foods.^[39]

The fruit of the sea-buckthorn

[edit]Oils from melon and gourd seeds

Watermelon seed oil, extracted from the seeds of Citrullus vulgaris, is used in cooking in West Africa.

Members of the Cucurbitaceae include gourds, melons, pumpkins, and squashes. Seeds from these plants are noted for their oil content, but little information is available on methods of extracting the oil. In most cases, the plants are grown as food, with dietary use of the oils as a byproduct of using the seeds as food.^[40]

Bitter gourd oil, from the seeds of Momordica charantia. High in α-Eleostearic acid. Of current research interest for its potential anti-carcinogenic properties.^[41]
Bottle gourd oil, extracted from the seeds of the Lagenaria siceraria, widely grown in tropical regions. Used as an edible oil.^[42]
Buffalo gourd oil, from the seeds of the Cucurbita foetidissima, a vine with a rank odor, native to southwest North America.^[43]
Butternut squash seed oil, from the seeds of Cucurbita moschata, has a nutty flavor that is used for salad dressings, marinades, and sautéeing.^[44]
Egusi^{[note 1]} seed oil, from the seeds of Cucumeropsis mannii naudin, is particularly rich in linoleic acid.^[45]
Pumpkin seed oil, a specialty cooking oil, produced in Austria, Slovenia and Croatia. Used mostly in salad dressings.^[46]
Watermelon seed oil, pressed from the seeds of Citrullus vulgaris. Traditionally used in cooking in West Africa.^[47]^[48]

[edit]Food supplements

A number of oils are used as food supplements (or "nutraceuticals"), for their nutrient content or purported medicinal effect. Borage seed oil,blackcurrant seed oil, and evening primrose oil all have a significant amount of gamma-Linolenic acid (GLA) (about 23%, 15–20% and 7–10%, respectively), and it is this that has drawn the interest of researchers.

Açaí oil, from the fruit of several species of the Açaí palm (Euterpe) grown in the Amazon region.^[49]^[50]
Black seed oil, pressed from Nigella sativa seeds, has a long history of medicinal use, including in ancient Greek, Asian, and Islamic medicine, as well as a topic of current medical research.^[51]^[52]^[53]
Blackcurrant seed oil, from the seeds of Ribes nigrum, used as a food supplement. High in gamma-Linolenic, omega-3 and omega-6 fatty acids.^[54]
Borage seed oil, from the seeds of Borago officinalis, with an omega-3 content comparable to blackcurrant seed oil and evening primrose oil.^[54]
Evening primrose oil, from the seeds of Oenothera biennis,^[55] the most important plant source of gamma-Linolenic acid, particularly because it does not contain alpha-Linolenic acid.^[54]^[56]
Flaxseed oil (called linseed oil when used as a drying oil), from the seeds of Linum usitatissimum. High in omega-3 and lignans, which can be used medicinally. A good dietary equivalent to fish oil.^[57] Easily turns rancid.^[58]

[edit]Other edible oils

Carob seed pods, used to make carob pod oil.

Amaranth oil, from the seeds of grain amaranth species, including Amaranthus cruentus and Amaranthus hypochondriacus, high in squalene andunsaturated fatty acids.^[59]
Apricot oil, similar to almond oil, which it resembles. Used in cosmetics.^[60]
Apple seed oil, high in linoleic acid.^[61]
Argan oil, from the seeds of the Argania spinosa, is a food oil from Morocco^[62] developed through a women's cooperative founded in the 1990s,^{[note 2]} that has also attracted recent attention in Europe.
Avocado oil, an edible oil^[63] used primarily in the cosmetics and pharmaceutical industries.^[64]^[65] Unusually high smoke point of 510°F.^[66]
Babassu oil, from the seeds of the Attalea speciosa, is similar to, and used as a substitute for, coconut oil.^[67]
Ben oil, extracted from the seeds of the Moringa oleifera. High in behenic acid. Extremely stable edible oil. Also suitable for biofuel.^[68]
Borneo tallow nut oil, extracted from the fruit of species of genus Shorea. Used as a substitute for cocoa butter, and to make soap, candles, cosmetics and medicines in places where the tree is common.^[69]
Cape chestnut oil, also called yangu oil, is a popular oil in Africa for skin care.^[70]
Carob pod oil (Algaroba oil), from carob, with an exceptionally high essential fatty acid content.^[71]^[72]
Cocoa butter, from the cacao plant, is used in the manufacture of chocolate, as well as in some ointments and cosmetics; sometimes known as theobroma oil ^[73]
Cocklebur oil, from species of genus Xanthium, with similar properties to poppyseed oil, similar in taste and smell to sunflower oil.^[74]^[75]
Cohune oil, from the Attalea cohune (cohune palm) used as a lubricant, for cooking, soapmaking and as a lamp oil.^[76]

Coriander seeds are the source of an edible pressed oil, Coriander seed oil.

Coriander seed oil, from coriander seeds, used in a wide variety of flavoring applications, including gin and seasoning blends.^[77] Recent research has shown promise for use in killing food-borne bacteria, such as E. coli.^[78]
Date seed oil, extracted from date pits.^[79] Its low extraction rate and lack of other distinguishing characteristics make it an unlikely candidate for major use.^[80]
Dika oil, from Irvingia gabonensis seeds, native to West Africa. Used to make margarine, soap and pharmaceuticals, where is it being examined as a tablet lubricant. Largely underdeveloped.^[81]^[82]
False flax oil made of the seeds of Camelina sativa. One of the earliest oil crops, dating back to the 6th millennium B.C.^[83] Produced in modern times in Central and Eastern Europe; fell out of production in the 1940s.^[84] Considered promising as a food or fuel oil.^[85]
Grape seed oil, a cooking and salad oil, also sprayed on raisins to help them retain their flavor.^[86]
Hemp oil, a high quality food oil^[87] also used to make paints, varnishes, resins and soft soaps.^[88]
Kapok seed oil, from the seeds of Ceiba pentandra, used as an edible oil, and in soap production.^[89]
Kenaf seed oil, from the seeds of Hibiscus cannabinus. An edible oil similar to cottonseed oil, with a long history of use.^[90]^[91]
Lallemantia oil, from the seeds of Lallemantia iberica, discovered at archaeological sites in northern Greece.^[92]
Mafura oil, extracted from the seeds of Trichilia emetica. Used as an edible oil in Ethiopia. Mafura butter, extracted as part of the same process when extracting the oil, is not edible, and is used in soap and candle making, as a body ointment, as fuel, and medicinally.^[93]
Marula oil, extracted from the kernel of Sclerocarya birrea. Used as an edible oil with a light, nutty flavor. Also used in soaps. Fatty acid composition is similar to that of olive oil.^[94]^[95]
Meadowfoam seed oil, highly stable oil, with over 98% long-chain fatty acids. Competes with rapeseed oil for industrial applications.^[96]
Mustard oil (pressed), used in India as a cooking oil. Also used as a massage oil.^[97]

Poppy seeds, used to make poppyseed oil

Nutmeg butter, extracted by expression from the fruit of cogeners of genus Myristica. Nutmeg butter has a large amount of trimyristin. Nutmeg oil, by contrast, is an essential oil, extracted by steam distillation.^[98]
Okra seed oil, from Abelmoschus esculentus. Composed predominantly of oleic and linoleic acids.^[99] The greenish yellow edible oil has a pleasant taste and odor.^[100]
Papaya seed oil, high in omega-3 and omega-6, similar in composition to olive oil.^[101] Not to be confused with papaya oil produced bymaceration.^[102]
Perilla seed oil, high in omega-3 fatty acids. Used as an edible oil, for medicinal purposes in Asian herbal medicine, in skin care products and as a drying oil.^[103]^[104]
Persimmon seed oil, extracted from the seeds of Diospyros virginiana. Dark, reddish brown color, similar in taste to olive oil. Nearly equal content ofoleic and linoleic acids.^[105]
Pequi oil, extracted from the seeds of Caryocar brasiliense. Used in Brazil as a highly prized cooking oil.^[106]
Pili nut oil, extracted from the seeds of Canarium ovatum. Used in the Philippines as an edible oil, as well as for a lamp oil.^[107]
Pomegranate seed oil, from Punica granatum seeds, is very high in punicic acid (which takes its name from pomegranates). A topic of current medical research for treating and preventingcancer.^[108]^[109]
Poppyseed oil, long used for cooking, in paints, varnishes, and soaps.^[110]^[111]^[112]^[113]
Prune kernel oil, marketed as a gourmet cooking oil^[114]^[115] Similar in composition to peach kernel oil.^[116]
Quinoa oil, similar in composition and use to corn oil.^[117]
Ramtil oil, pressed from the seeds of the one of several species of genus Guizotia abyssinica (Niger pea) in India and Ethiopia.^[118]^[119]
Rice bran oil is a highly stable cooking and salad oil, suitable for high-temperature cooking.^[66]^[120] It also has potential as a biofuel.^[121]
Royle oil, pressed from the seeds of Prinsepia utilis, a wild, edible oil shrub that grows in the higher Himalayas. Used medicinally in Nepal.^[122]

Shea nuts, from which shea butter is pressed

Sacha inchi oil, from the Peruvian Amazon. High in behenic, omega-3 and omega-6 fatty acids.^[123]^[124]
Sapote oil, used as a cooking oil in Guatemala.^[125]
Seje oil, from the seeds of Jessenia bataua. Used in South America as an edible oil, similar to olive oil, as well as for soaps and in the cosmeticsindustry.^[126]
Shea butter, much of which is produced by poor, African women. Used primarily in skin care products and as a substitute for cocoa butter inconfections and cosmetics.^[127]^[128]
Taramira oil, from the seeds of the arugula (Eruca sativa), grown in West Asia and Northern India. Used as a (pungent) edible oil after aging to remove acridity.^[129]^[130]
Tea seed oil (Camellia oil), widely used in southern China as a cooking oil. Also used in making soaps, hair oils and a variety of other products.^[131]^[132]
Thistle oil, pressed from the seeds of Silybum marianum.^[133] A good potential source of special fatty acids, carotenoids, tocopherols, phenolcompounds and natural anti-oxidants,^[134] as well as for generally improving the nutritional value of foods.^[135]
Tigernut oil (or nut-sedge oil) is pressed from the tuber of Cyperus esculentus. It has properties similar to soybean, sunflower and rapeseed oils.^[136] It is used in cooking and making soap^[137]and has potential as a biodiesel fuel.^[136]
Tobacco seed oil, from the seeds of Nicotiana tabacum and other Nicotiana species. If purified, is suitable for edible purposes.^[138]
Tomato seed oil is a potentially valuable by-product, as a cooking oil, from the waste seeds generated from processing tomatoes.^[139]
Wheat germ oil, used nutritionally and in cosmetic preparations,^[140] high in vitamin E and octacosanol.^[141]

[edit]Oils used for biofuel

[edit]Multipurpose oils also used as biofuel

The oils listed immediately below are all (primarily) used for other purposes – all but tung oil are edible – but have been considered for use as biofuel.

Castor oil, lower cost than many candidates. Kinematic viscosity may be an issue.^[144]
Coconut oil (copra oil), promising for local use in places that produce coconuts.^[145]
Colza oil, from Brassica rapa, var. oleifera (turnip) is closely related to rapeseed (or canola) oil. It is a major source of biodiesel in Germany.^[146]
Corn oil, appealing because of the abundance of maize as a crop.
Cottonseed oil, the subject of study for cost-effectiveness as a biodiesel feedstock.^[147]^[148]
False flax oil, from Camelina sativa, used in Europe in oil lamps until the 18th century.^[85]
Hemp oil, relatively low in emissions. Production is problematic in some countries because of its association with marijuana.^[149]^[150]
Mustard oil, shown to be comparable to Canola oil as a biofuel.^[151]
Palm oil, very popular for biofuel, but the environmental impact from growing large quantities of oil palms has recently called the use of palm oil into question.^[152]
Peanut oil, used in one of the first demonstrations of the Diesel engine in 1900.^[143]
Radish oil. Wild radish contains up to 48% oil, making it appealing as a fuel.^[153]
Rapeseed oil, the most common base oil used in Europe in biodiesel production.^[142]
Ramtil oil, used for lighting in India.^[154]
Rice bran oil, appealing because of lower cost than many other vegetable oils. Widely grown in Asia.^[155]
Safflower oil, explored recently as a biofuel in Montana.^[156]
Salicornia oil, from the seeds of Salicornia bigelovii, a halophyte (salt-loving plant) native to Mexico.^[157]
Soybean oil, not economical as a fuel crop, but appealing as a byproduct of soybean crops for other uses.^[142]
Sunflower oil, suitable as a fuel, but not necessarily cost effective.^[158]
Tigernut oil has been described by researchers in China as having "great potential as a biodiesel fuel."^[136]
Tung oil, referenced in several lists of vegetable oils that are suitable for biodiesel.^[159] Several factors in China produce biodiesel from tung oil.^[160]

[edit]Inedible oils used only or primarily as biofuel

[edit]Drying oils

[edit]Other oils

A number of pressed vegetable oils are either not edible, or not used as an edible oil.

The fruit of the amur cork tree

Castor beans are the source of castor oil

Amur cork tree fruit oil, pressed from the fruit of the Phellodendron amurense. It has been studied for insecticidal use.^[179]^[180]
Artichoke oil, extracted from the seeds of the artichoke fruit, is an unsaturated semi-drying oil with potential applications in making soap, shampoo, alkyd resin and shoe polish.^[181]
Balanos oil, pressed from the seeds of Balanites aegyptiaca, was used in ancient Egypt as the base for perfumes.^[68]
Bladderpod oil, pressed from the seeds of Lesquerella fendleri, native to North America. Rich in lesquerolic acid, which is chemically similar to thericinoleic acid found in castor oil. Many industrial uses. Possible substitute for castor oil as it requires much less moisture than castor beans.^[182]
Brucea javanica oil, extracted from the seeds of the Brucea javanica. The oil has been shown to be effective in treating certain cancers.^[183]^[184]
Burdock oil (Bur oil) extracted from the root of the burdock. Used as an herbal remedy for scalp conditions.^[185]
Candlenut oil (Kukui nut oil), produced in Hawai'i, used primarily for skin care products.^[186]
Carrot seed oil (pressed), from carrot seeds, used in skin care products.^{[note 5]}^[187]
Castor oil, with many industrial and medicinal uses. Castor beans are also a source of the toxin ricin.^[142]
Chaulmoogra oil, from the seeds of Hydnocarpus wightiana, used for many centuries, internally and externally, to treat leprosy.^[188] Also used to treat secondary syphilis, rheumatism, scrofula, and in phthisis.^[189]^[190]
Crambe oil, extracted from the seeds of the Crambe abyssinica. High in erucic acid, used as an industrial lubricant, a corrosion inhibitor, and as an ingredient in the manufacture of synthetic rubber.^[191]^[192]
Croton oil (tiglium oil) is pressed from the seeds of Croton tiglium. Highly toxic, it was formerly used as a drastic purgative.^[193]
Cuphea oil, from a number of species of genre Cuphea. Of interest as sources of medium chain triglycerides.^[194]
Honesty oil, from the seeds of Lunaria annua, which contain 30–40% oil. The oil is particularly rich in long chain fatty acids, including erucic andnervonic acid, making it suitable for certain industrial purposes.^[88]^[195]
Illipe butter, from the nuts of the Shorea stenoptera. Similar to cocoa butter, but with a higher melting point. Used in cosmetics.^[196]^[197]
Jojoba oil, used in cosmetics as an alternative to whale oil spermaceti.^[198]
Mango oil, pressed from the stones of the mango fruit, is high in stearic acid, and can be used for making soap.^[199]
Mowrah butter, from the seeds of the Madhuca latifolia and Madhuca longifolia, both native to India. Crude Mowrah butter is used as a fat for spinning wool, for making candles and soap. The refined fat is used as an edible fat and vegetable ghee in India.^[43]
Neem oil, from Azadirachta indica, a brownish-green oil with a high sulfur content, used in cosmetics, for medicinal purposes, and as an insecticide.^[200]
Ojon oil extracted from the nut of the American palm (Elaeis oleifera). Oil extracted from both the nut and husk is also used as an edible oil in Central and South America. Commercialized by a Canadian businessman in the 1990s.^[201]^[202]
Rose hip seed oil, used primarily in skin care products, particularly for aging or damaged skin.^[203]
Rubber seed oil, pressed from the seeds of the Rubber tree (Hevea brasiliensis), has received attention as a potential use of what otherwise would be a waste product from making rubber. It has been explored as a drying oil in Nigeria,^[204] as a diesel fuel in India^[205] and as food for livestock in Cambodia and Vietnam.^[206]
Sea buckthorn oil, derived from Hippophae rhamnoides, produced in northern China, used primarily medicinally.^[207]
Sea rocket seed oil, from the halophyte Cakile maritima, native to north Africa, is high in erucic acid, and therefore has potential industrial applications.^[208]
Snowball seed oil (Viburnum oil), from Viburnum opulus seeds. High in tocopherol, carotenoides and unsaturated fatty acids. Used medicinally.^[209]
Tall oil, produced as a byproduct of wood pulp manufacture. A further byproduct called tall oil fatty acid (TOFA) is a cheap source of oleic acid.^[210]
Tamanu or foraha oil^[211] from the Calophyllum tacamahaca, is important in Polynesian culture, and, although very expensive,^[211] is used for skin care.^[212]
Tonka bean oil (Cumaru oil), used medicinally in Brazil.^[213]
Ucuhuba seed oil, extracted from the seeds of Virola surinamensis, is unusually high in myristic acid.^[212]

Weatherford Oil Tool M.E. Ltd, Kakinada

2012-07-21T10:25:00.000-07:00

Weatherford Oil Tool M.E. Ltd, Kakinada

Title

Weatherford Oil Tool M.E. Ltd

Caption

Weatherford

Since

2004

Contact Person

D.R.Naik

Address

Plot No: 5A3, IDA, ADB Road, Vakalapudi, Kakinada - 05

Landmark

Near Aker Solutions

Contact no's

Click here to view

E-Mail

dumavath.naik@me.weatherford.com

Website

www.weatherford.com

Working Hours

9:30 a.m. To 6:00 p.m.

Description

Weatherford International Ltd is one of the largest global providers of advanced products and services that span the drilling,evaluation, completion, production and intervention cycles of oil and natural gas wells. Weatherford has two key objectives--efficiency and productivity. Weatherford strives for efficiency, both in terms of delivering results for its clients as well as leveraging its worldwide infrastructure. The ultimate goal in both cases is to help reduce costs and increase well productivity.

Gujarat State Petroleum Corporation Ltd., Kakinada

2012-07-21T10:24:00.002-07:00

Gujarat State Petroleum Corporation Ltd., Kakinada

Title

Gujarat State Petroleum Corporation Ltd.

Caption

A Govt. Of Gujarat Undertaking

Since

2000

Contact Person

Radio Room

Address

STC Ware House Complex, Near Port Godowns, Beach Road,Kakinada - 05

Landmark

Near M.M.T.C. Ware House

Contact no's

Click here to view

Website

www.gspcgroup.com

Working Hours

8:30 a.m. To 6:00 p.m.

Description

The Rs. 3900 crore Gujarat State Petroleum Corporation (GSPC) is the flagship concern of the GSPC Group involved in exploration and production (E&P). In its earlier avatar, GSPC went about pursuing projects in the downstream hydrocarbon sector. However, the company expanded its vision and scope of activities when it scented the opportunity that came with the privatization of the hydrocarbon sector in the nineties.
The GSPC group is fully aware of a changing graph in the power business and has evolved strategically as a multidimensional highly integrated conglomerate and a leading energy enterprise.
For further details visit our website.

Acalmar Oils & Fats Limited, Kakinada

2012-07-21T10:23:00.002-07:00

Acalmar Oils & Fats Limited, Kakinada

Title

Acalmar Oils & Fats Limited

Since

2001

Contact Person

V.V.V.Seshagiri Rao

Address

ADB Road., Vakalapudi, Kakinada - 05

Landmark

Near Light House

Contact no's

Click here to view

E-Mail

itoperation_kkd@acalmar.com

Website

www.acalmar.com

Working Hours

9:00 a.m. To 6:00 p.m.

Description

We are the importers of edible oil and oil products. We deal with food, beverages,and fats

Oil Refining

2012-07-21T10:20:00.004-07:00

Oil Refining

Neutralizing: The Crude Oil temporarily stored in Crude Oil Tank is pumped into neutralizing tank by Oil Pump. The oil is mixed with alkali lye in the Mixer and neutralized in Neutralizing Tank, free fatty acid has been neutralized or saponified to be Soapstock.

Physical refining: Physical Refining means removing gum in the oil in the process of degumming and removing the FFA in process of deodorizing by steam. It has the following features:
1. Less oil loss and high oil refining ratio.
2. No water wasted in process of production.
3. More FFA is distilled out.
4. More suitable oil with high acid value and low gum-impurity.

Chemical Refining: Chemical Refining means removing FFA in a way (acid-base neutralization). Gum and soapfoot is separated by centrifuges. Chemical refining has following features:
1. Fine adaptability and less requirement of crude oil quality.
2. Consistent product oil.
3. Less clay is added in compared with physical refining.
Oil Refining process can remove phospholipid, FFA, pigment, off-flavor and other impurities. It includes the following sections: Oil Dugumming, Oil Deacidifying, Oil Bleaching, Oil Deodorizing and Oil Dewaxing.

Oil Bleaching: High-activity clay is added into oil, mix and heat mixture of oil and clay to make the small particle of pigment absorbed on the crystal of clay. This machine is of perfect mechanism, reliable performance and is well a configured piece of equipment.
Oil Deodorizing: The heat of most bleached oil is recovered by heat exchangers. The bleached oil is heated to the process temperature by mineral oil or high pressure steam and then the oil enters into the combined deodorizer, the deodorizer is a combined type: the upper is the packing structure, which is used to remove odor components like FFA, the lower is plate is used for heat bleaching and making product quality more consistent. Oil coming from the deodorizer is cooled and stored after series of heat exchange, volatile like FFA is collected and stored as by products.

Oil Dewaxing: It can improve oil palatability, so it plays an important role in the quality of finished oil. At the same time, dewaxing can improve oil transparency and brightness. At present, winterizing method is verypopular to dewaxing.

Workshop View

		Oil Deodorzing
	Oil Degumming

	Oil Bleaching

	Oil Dewaxing and Fraction

The Cream Always Rises

2012-07-21T10:19:00.002-07:00

The Cream Always Rises

7062010

Every morning when I go out to milk the goats, I carry with me the fantasy that my children are naturally going to be curious about what I am doing — they will be drawn to me and I will just narrate for them all of my activities. They will ask me questions and I will offer them to take a try and pretty soon they will be active participants in gardening, goat wrangling and beekeeping. They will absorb all of my values regarding developing a simple, productive life away from computers and television. It’s a nice fantasy.

The other morning when I was out happily milking the goats, I realized my son was inside, parked in front of the television. He is only four and a half, but he is highly proficient in using the remote control, my iPhone and finding Pog.com on Danae’s laptop. Given the choice most days he will choose to zone out playing video games or watch TV until my youngest niece wakes up and he has someone to actively play with. I realize that the literacies we practice require active participation in order to acquire them in the first place. We do not just see trains running down the track and know how to purchase a fare to ride them any more than we know how to play video games just because we can navigate to Pog.com. The choices I make as a parent — whether to take my children on a train ride or to allow them freedom of access to a laptop with wireless internet — determine the experiences my children will have and will ultimately have an effect on how they view the world. So, in order for my children to develop a literacy of rustic life they need to be active participants in all that I do — the work and the rewards. That evening, when both children were home, Danae went out to milk the goats and I did something I hadn’t yet done since Rainbow and Redwood became a part of our little compound — I didn’t invite the children to come out and watch or give milking a try, I required them to come outside to do something to help.

Gwen milks Rainbow for the first time on her own.

Kaherdin does not yet feel comfortable with the idea of milking, but he was more than happy to pick herbs from our herb garden and feed them to each goat as they had their turn in the stanchion. He talked to them soothingly and scratched them on their heads while Gwen jumped right in and announced she wanted to milk both goats all on her own. She started out squeezing the tips of Redwood’s teats and getting nothing. Little by little Danae worked with her until she was able to consistently get something into the cup. I took over and worked with her on her grip until the motion became second nature. You could see the confidence building in her posture as strong streams of milk began falling into her cup. This was an excellent start — me straddling the same stool as Gwen, she in front of me, my arms tightly on either side of her as I held the cup, coached and cheered her with every squeeze.

The next morning Danae called me outside. Gwen was doing it all on her own.

In the meantime Danae found a free hot tub on Craigslist. We got rid our last spa right around the time Kaherdin was born. The drain didn’t work right so we had to suck all the water out with a shop vac each and every time the thing needed to be cleaned — which was often. It seemed to be growing increasingly more difficult to keep crud out of the tub and to keep the ph balanced. Also, we tapped into a 110 outlet across the wall from the kids’ bedroom and having a spa and Baby Mozart running at the same time was apparently too much for our circuitry. We would put the kids to bed, bring the baby monitor out with us and settle into the hot water for a minute or two before the motor would stop suddenly, as would the music in the kids room, and pretty soon we were cold, wet and now having to deal with a crying baby. The tub had become more of a burden than a pleasure so we decided to dump it off on someone looking for such a thing on Craigslist. This was nearly five years ago. Since then the forgetting hormones have set in and there have been many nights when my body has ached to be relieved of it’s weight, to have it’s temperature egged on by some steaming hot water, to have a space to have an intimate conversation without the distraction of the TV or the dishes. The forgetting hormones have kicked in — I want another hot tub.

Sunday we spent all day obsessed with renting a truck, going to pick up this beast of a tub (a 7′x7′ that seats eight). It took three women and three men from the neighborhood where we picked it up to get this thing loaded in, but once we got home we were three men short. Somehow Nicole, Danae and I managed to get the thing off the truck and onto the patio without killing ourselves. Now the trick is installing a new 220 line with its own circuit box. Danae is on it.

In all our crazy hot tub obsession we completely overlooked Sunday dinner. My plans of riding the Xtracycle to the farmer’s market to buy produce, for using the cream separator on all of our milk stores and of having the children make their own butter with their own personal tiny jars of cream had to be put on hold. This was a different kind of fantasy — of quality time in the hot tub with Danae in the kids to talk about our days, our thoughts, to be away from TV and amidst all of the work we’ve will be doing in our yard this summer. We’ll be right next to the chickens and the goats in our bubbling cauldron of joy.

One small reason we have goats has to do with Gwennie’s love of goat cheese. I am now trying to interest her in the processing of the milk she is now able to extract from the goats. I have tried my hand at making queso blanco and feta and I aim to expand my cheese-making repertoire, but what I’ve really been looking forward to is being able to get two different products from the same bucket of milk.

My Royal Blue Junior #33 hand-cranked cream separator. It's HUGE!

Saturday I finally set up the antique cream separator that I bought off of ebay. I had no way to verify that all of the parts would be included when it arrived. I bought it off a book seller who made a strong disclaimer that he had no idea how the thing worked so could not guarantee that it was complete or functional. It’s a Royal Blue Junior #33 — a massive piece of equipment for a small kitchen. The base is cast iron and has a wooden-handled crank. There are two spouts that sit atop the base to channel the separated liquids into their receptacles — cream to one side and skimmed milk to the other. On top of the spouts sits a massive metal basin that has a two-gallon capacity. Inside the base is something called the “bowl” a conical case that holds inside of it fourteen conical rings that, when the crank is operating at 60-65 turns per minute, spin to create the centrifugal force that causes the whole milk to separate into milk and cream.

This is the way the conical "bowl" component of the separator works.

It took and entire morning to finally figure out the process for getting this thing to work but, when we did, the feeling was amazing. The first run I wasn’t cranking quickly enough and much of the milk dribbled down out of an overflow hole. We gathered that into a bowl as it dripped over the side of our butcher block and put it back in. Try, try again. The second time we felt that the two liquids were not different enough in consistency. I realized that the milk was no longer at goat temperature (about 100 degrees). We needed to warm the milk in order to make the separation process more efficient. I got a pot on and warmed the milk and, on the third try, success! Not only could I breathe a sigh of relief that I hadn’t been ripped off with my ebay purchase, but I now had a human-powered machine that could separate our goat milk into skimmed milk for everyday use and cream for making butter and ice cream. A whole world had just opened up.

I immediately put the cream in the mixer to see if we could get butter and that would be the ultimate test of whether the separator worked and gave us pure cream. It failed miserably. I was a bit saddened but I also know enough to know that I’m usually missing something when a process isn’t working out. I found a website on how to make goat butter and read that the cream must be 24 hours old and at around 50-60 degrees in order to make good butter. I placed the cream in a jar and put it in the refrigerator and decided to try again later.

That night I thought I might give it another try. I retrieved the jar from the fridge and was about to get out the mixer when I remembered how on farm tours kids are often given a small jar of cream to shake into butter on their own. I started vigorously shaking the jar and within a few minutes I had a big butter ball. Immediately I decided that the kids would make their own butter for bread at Sunday dinner but, like I said above, Sunday dinner never happened. But something better did.

As I was resting in the recliner seat of our empty hot tub Gwen came up to me and said, “It’s time to milk the goats.” I looked at my phone to check the time and felt that it was about an hour too early. I tried to put her off a little by saying, well, that it was an hour too early, but she was persistent. I realized this was a seize or lose moment to make her a part of the lifestyle I am working so hard for. If I put her off again she may lose interest. I got up from my sunny spot and told her I would go wash the milk pail and get a clean rag to wash of the goat’s udders.

I got Redwood up on the stanchion and wiped her down then Gwen said, “Three squirts each.” She proceeded to do the three squirts on each teat to get out any dirt and to get the flow going, then she began to milk. This was Gwen, my child who loses interest in everything, taking the initiative to do a farm chore. She’s always loved animals, and maybe that has something to do with it. Milking is such an intimate chore, when done by hand. It’s skin, it’s lactation, it’s massaging a goat’s boobie to make sure you’ve gotten all the milk out. It’s personal.

Goat Shares even in our own back yard. Nicole completes her first solo milking, which she will continue every Monday so she and her family can enjoy a share of the fresh milk.

Earlier in the day I had promised my sister and her youngest daughter that they could have a turn milking — they had yet to try. I called them over then leaned in to Gwen and asked her if she would be their instructor. She gladly agreed. I had to take several deep breaths and just resign to the fact that we were going to lose milk, probably a lot of milk, in this process — goats stepping into the bucket, spills, general debris flying everywhere. We could get more tomorrow, but what could be gained here was irreplaceable. Gwen could manufacture her own motivation for milking by creating herself as the resident expert on the subject. We milked out Redwood fairly quickly because she is the less patient of the two goats, and got Rainbow up on the stanchion. I asked Gwen to start her lesson. She invited her cousin to sit on the milking stool then patiently showed her, again and again, how to get a proper hold on the teat. After Lindsey tired of trying it was my sister’s turn. Gwen got to show her aunt what she knew while I walked to the back of the property where Danae was picking apricots. By the time I helped pick a few branches worth and came back, Nicole was milking Rainbow solo as the kids had abandoned her in order to play with one another. Instead of becoming frustrated by Gwen’s abandonment of her duties, I couldn’t have been more proud. Just Friday I had been questioning my authenticity as a parent — using my farm chores as an escape from motherhood rather than an extension of it. Today Gwen was not only a bona fide milker, but a teacher and it started because I required her involvement then worked it into something she could really feel good about.

I think that this is what the goats are giving us — a flavor of authenticity in our daily lives. We have a necessary routine which provides us daily opportunities to find teaching moments for ourselves and our family. We have fresh food that needs to be processed and dealt with, animals that need to be cared for in order to provide for us, and in these things we feel that we are doing work that matters. In our relationship with these animals we are bound to a schedule and less certain freedoms but we are gaining so much more. They are making us work for what we get and, in the process, we are growing to feel more able, more confident, more us.

Separations

2012-07-21T10:18:00.002-07:00

Separations

Description

In order to conduct a separation you should familiarise yourself with the function of the low mix sleeve

During separations, a sleeve (2) (low mix sleeve) is installed to protect the entering liquids (and further mixing) from the spinning rotor (3). The liquids after entering the housing drop to the base plate of the centrifuge, which has directional vanes (4) that direct the liquids to the entry point (5) at the base of the spinning rotor.

Inside the rotor at the base of the vane package (6) a mild pumping action takes place to continually fill the rotor at the required feed rate.

As the liquids are entering the spinning rotor they contact with a deflector plate (7), which forces the mixed liquids to the outside of the rotor wall at the bottom of the rotor. At this point the mixed liquids are first subjected to the "G" force created by the spinning rotor.

As the unit is continually fed the liquid continually moves up the inside of the rotor sleeve and is subjected to centrifugal force between 100 G to 600 G inside the separation zone (8). The height of the rotor is significant, as this, along with the flow rate fed to the unit will determine the length of time (the retention time) the liquids are subjected to "G" force and therefore the optimum efficiency of the separation.

Light & Heavy Phase DischargeDuring the period of retention the mixed phases inside the spinning rotor are subjected to the "G" forces and two distinct phases will appear inside the rotor. When the two, now separate phases reach the top of the rotor they optimise at the centre of the "Fixed" light phase weir (9). At this point the now separated phases are able to exit the top of the rotor. There are 4 heavy phase outlets (10) which allow the heavy phase liquid to enter the top heavy phase compartment past the pre determined changeable heavy phase weir (11) and out through the heavy phase discharge outlet (12).

The light phase will gradually separate from the heavy phase and sit "ontop" as both liquids spin in the rotor. As both phases reach the fixed light phase weir (13) the optimum point, at its centre, which is determined by the rotor speed. As the rotor continues to fill from the bottom the light phase volume at the optimum point will exit from the light phase exit (14) into the light phase collector ring (15) and out via the light phase discharge nozzle (16). The heavy Phase exits the rotor at point (10), up into the heavy phase chamber (17) out into the heavy phase collector ring (18) and discharged out of the heavy phase discharge outlet (12).

Introduction

Separations

Extractions & Water washes

Multi stage, gravity fed, continuous counter current Extractions

FABs

Introduction

2012-07-21T10:17:00.000-07:00

Centrifuges accelerate liquid- liquid separations by enhancing the specific gravity difference between the two liquid concerned Two immiscible liquids with slight gravity differences can be separated rapidly and cleanly and on a continuous basis by a centrifuge. Liquid/ liquid dispersions that require hours to separate at 1”G” can be greatly enhanced both in speed and efficiency at 200 “G”.

There are 4 basic operational functions of the centrifuge. The set up differs slightly for each of the process’s which are;

1. Separations
2. Extractions and water washes (Mixing and separation)
3. Multi stage, gravity fed, continuous counter current Extractions
4. Re-actions

In order to conduct a separation using equipment from CINC SOLUTIONS you should familiarise yourself with the function of the low mix sleeve and how the unit optimizes the separation at the top of the rotor on fixed light phase weir, before separating by the designated discharge outlets.

Mixed liquids of any ratio and with differing Specific Gravities are continually pumped (low pressure) or gravity fed into one of the inlets (1) provided on the housing (the spare (12) is blocked off). During separations, a sleeve (2) (low mix sleeve option) is installed to protect the liquids entering the housing from contacting the spinning rotor (3) (and therefore preventing further mixing before separating). The liquids, after entering the housing drop to the base plate of the centrifuge, which has directional vanes (4) that direct the liquids to the entry point (5) at the base of the spinning rotor.
Inside the rotor at the base of the vane package (6) a mild pumping action takes place to continually fill the rotor at the pre determined feed rate. As the liquids are entering the spinning rotor they contact with a deflector plate (7), which forces the mixed liquids to the outside of the rotor wall at the bottom of the rotor. At this point the mixed liquids are first subjected to the “G” force created by the spinning rotor. As the unit is continually fed the liquid gradually and continually moves up the inside of the rotor sleeve and is subjected to centrifugal force between 100 “G” to 600 “G” inside the separation zone (8). The internal height of the rotor is significant, as this, along with the liquid flow rate fed to the unit will determine the length of time (the retention time) the liquids are subjected to “G” force and are therefore en hanced to be an efficient separation. The slower the unit feeds, the longer the liquids remain in the rotor, the longer they are subjected to “G” force, the better the separation efficiency. This is significant if liquids have specific gravities that are close together or are emulsified and are subsequently difficult to separate.

Light & Heavy Phase DischargeDuring the period of retention the mixed phases inside the spinning rotor are subjected to the “ G “ forces and two distinct phases will appear inside the rotor. The heavy phase will move toward the rotor wall and the light phase will settle on top of the heavy phase. When the two, now separate phases reach the top of the rotor they optimize at the centre of the “Fixed” light phase weir (9). At this point the now separated phases are able to exit the top of the rotor for discharge. There are 4 heavy phase exit points at the top of the rotor (10) which allow the heavy phase liquid to enter the top heavy phase chamber (16) past the pre determined changeable heavy phase weir (11) and out through the heavy phase discharge outlet (12). The light phase will gradually separate from the heavy phase and sit “on top” as both liquids spin in the rotor. As both phases reach the fixed light phase weir (9) the optimum separation point, is its centre. This is the optimum separation point at which physical separation takes place sending the two separated phases into different discharge outlets in the housing.

Evidence of carryover exiting a phase discharge can be corrected by adjusting the motor RPM. Whilst it is recognised the optimum separation position is the centre of the fixed light phase weir allowing both phases to exit the required discharge there may be occasions when ratios of phases dictate slight adjustment of this position are required. Slight increase or decrease of the motor speed will increase or decrease the amount of “G” force inside the unit. This will effect the position of the optimum separate phase on the fixed light phase weir (9), moving this phase to or from its exit point by increasing or decreasing the motor speed and can be used to adjust the unit in order to prevent carryover.

As the rotor continues to fill from the bottom the light phase volume at the optimum point will exit from the light phase exit (13) into the light phase collector ring (14) and out via the light phase discharge outlet (15). The heavy Phase exits the rotor at point (10), up into the heavy phase chamber (16) out into the heavy phase collector ring (17) and discharged out of the heavy phase discharge outlet (12).

Centrifugal seperator

2012-07-21T10:16:00.000-07:00

Sunflower oil

2012-07-21T02:04:00.000-07:00

Sunflower oil is the non-volatile oil expressed from sunflower (Helianthus annuus) seeds. Sunflower oil is commonly used in food as a frying oil, and in cosmeticformulations as an emollient. Sunflower oil was first industrially produced in 1835 in the Russian Empire. The world's largest sunflower oil producers now are Ukraine andRussia ^[1].

[hide]

[edit]Composition

Sunflower oil is mainly a triglyceride, a typical constituent is shown.^[2] The British Pharmacopoeia lists the following profile:^[3]

Palmitic acid : 4 - 9%
Stearic acid : 1 - 7%
Oleic acid : 14 - 40%
Linoleic acid : 48 - 74%

Sunflower oil is mainly triglycerides (fats), typically derived from the fatty acids linoleic acid (with is doubly unsaturated) and oleic acid.

Several types of sunflower oils are produced, such as high linoleic, high oleic and mid oleic. Mid-linoleic sunflower oil typically has at least 69% linoleic acid. High oleic sunflower oil has at least 82% oleic acid. Variation in unsaturated fatty acids profile is strongly influenced by both genetics and climate. In the last decade, high stearic sunflower lines have been developed in Spain to avoid the use of partially hydrogenated vegetable oils in the food industry.

Sunflower oil also contains lecithin, tocopherols, carotenoids and waxes. Sunflower oil's properties are typical of a vegetable triglyceride oil. Sunflower oil is produced from oil type sunflower seeds. Sunflower oil is light in taste and appearance and has a highvitamin E content. It is a combination of monounsaturated and polyunsaturated fats with low saturated fat levels.

[edit]Physical properties

Sunflower oil is liquid at room temperature. The refined oil is clear and slightly amber-colored with a slightly fatty odor.

Smoke point (refined)	232 °C	450 °F^[4]
Smoke point (unrefined)	107 °C	225 °F^[4]
Density (25 °C)	918.8 kg/m³^[5]
Refractive index (25 °C)	≈1.4646^[5]

Viscosity, 25°C, unrefined: 0.04914 kg/(M*S)^[6]

[edit]Uses

As a frying oil, sunflower oil behaves as a typical vegetable triglyceride. In cosmetics, it has smoothing properties and is considered noncomedogenic. Only the high oleic variety possesses shelf life sufficient for commercial cosmetic formulation. Sunflower oil's INCI name is Helianthus annuus (Sunflower) Seed Oil.

Sunflower oil is also an ingredient in sunflower butter.

Sunflower oil can be used to run diesel engines when mixed with diesel in the tank.

[edit]Nutrition

itional value per 100 g (3.5 oz)
Energy	3,699 kJ (884 kcal)
Carbohydrates	0 g
Fat	100 g
- saturated	9.748 g
- monounsaturated	83.594 g
- polyunsaturated	3.798 g
Protein	0 g
Vitamin E	41.08 mg (274%)
Vitamin K	5.4 μg (5%)
Percentages are relative to US recommendations for adults.

Sunflower oil, standard
Nutritional value per 100 g (3.5 oz)
Energy	3,699 kJ (884 kcal)
Carbohydrates	0 g
Fat	100 g
- saturated	10.3 g
- monounsaturated	19.5 g
- polyunsaturated	65.7 g
Protein	0 g
Vitamin E	41.08 mg (274%)
Vitamin K	5.4 μg (5%)
Percentages are relative to US recommendations for adults.

Sunflower oil (NuSun), mid oleic
Nutritional value per 100 g (3.5 oz)
Energy	3,699 kJ (884 kcal)
Carbohydrates	0 g
Fat	100 g
- saturated	9.009 g
- monounsaturated	57.344 g
- polyunsaturated	28.962 g
Protein	0 g
Vitamin E	41.08 mg (274%)
Vitamin K	5.4 μg (5%)
Percentages are relative to US recommendations for adults.

Several varieties of sunflower oilseeds have been developed by unflower oil, high oleic (70% and over)Nutrstandard genetic methods. The original oilseed was high in glyceryl linoleate. A premium high oleic strain was developed in the late twentieth century. Early in the 21^st century, a mid oleic strain marketed as Nu-Sun was introduced as an improved frying oil that would have a low level of saturated fat, but would not require hydrogenation. These three major strains differ greatly in their levels of monounsaturated and polyunsaturated fats. There are also minor differences in their saturated fat content.

Comparative properties of common cooking fats (per 100g)
	Total fat	Saturated fat	Monounsaturated fat	Polyunsaturated fat	Smoke point
Sunflower oil	100g	11g	20g	69g	225 °C (437 °F)^[a]
Soybean oil	100g	16g	23g	58g	257 °C (495 °F)^[a]
Olive oil	100g	14g	73g	11g	190 °C (374 °F)^[a]
Corn oil	100g	15g	30g	55g	230 °C (446 °F)^[a]
Peanut oil	100g	17g	46g	32g	225 °C (437 °F)^[a]
Vegetable shortening (hydrogenated)	71g	23g (34%)	8g (11%)	37g (52%)	165 °C (329 °F)^[a]
Lard	100g	39g	45g	11g	190 °C (374 °F)^[a]
Suet	94g	52g (55%)	32g (34%)	3g (3%)	200°C (400°F)
Butter	81g	51g (63%)	21g (26%)	3g (4%)	150 °C (302 °F)^[a]
^ ^a ^b ^c ^d ^e ^f ^g ^h The Culinary Institute of America (2011). The Professional Chef. New York: Wiley. ISBN 0-470-42135-5.

[edit]Health benefits

There are a variety of health benefits associated with the consumption of sunflower oil.

[edit]Diet and cardiovascular benefits

Sunflower oil is high in the essential vitamin E and low in saturated fat. The two most common types of sunflower oil are linoleic and high oleic. Linoleic sunflower oil is a common cooking oil that has high levels of polyunsaturated fat. It is also known for having a clean taste and low levels oftrans fat. High oleic sunflower oils are classified as having monounsaturated levels of 80% and above. Newer versions of sunflower oil have been developed as a hybrid containing linoleic acid. They have monounsaturated levels lower than other oleic sunflower oils. The hybrid oil also has lower saturated fat levels than linoleic sunflower oil.^[7]

[edit]Restaurant and food industry uses

Restaurants and food manufacturers are becoming aware of the health benefits of sunflower oil. The oil can be used in conditions with extremely high cooking temperatures. It may also help food stay fresher and healthier for longer periods of time.^[8] Food manufacturers are starting to use sunflower oil in an effort to lower the levels of trans fat in mass produced foods. A number of common snack foods currently contain sunflower oil, including NewYork Fries French fries, Majans bhuja Mix healthy snacks, the Sri Lankan style Bombay Mix - Rani Mix, Kettle Chips, Sun Chips, Sunflower Chips, Ruffles, Walkers and Lay's potato chips. The recipe of Lay's potato chips was modified in late 2006 to use sunflower oil as the only frying oil;^[9]by 2009, the recipe again included other "natural oils".^[10]

[edit]Skin protectant

Sunflower oil, like other oils, can retain moisture in the skin. It may also provide a protective barrier that resists infection in premature infants. Studies using sunflower oil have been conducted involving low birth weight infants who are often susceptible to infection due to their underdeveloped skin. The study determined that infants receiving a daily skin treatment of sunflower oil were 41% less likely to develop infections in the hospital.^[11]

[edit]Negative health effects

A high consumption of omega-6 polyunsaturated fatty acids, which are found in most types of vegetable oil, including sunflower oil, may increase the likelihood postmenopausal women may develop breast cancer.^[12] A similar effect was observed on prostate cancer - however, the study was performed on mice.^[13] Another study indicated that, when heated to frying temperature for extended periods, sunflower oil produces aldehydes, which may be associated with some neurodegenerative diseases.^[14]

[edit]Preparation and storage

Because sunflower oil is primarily composed of healthier but less stable polyunsaturated and monounsaturated fatty acids, it can be particularly susceptible to damage by heat and light. Keeping sunflower oil at low temperatures both during processing and storage can help to minimize rancidity and nutrient loss, as can storage in darker amber-colored bottles.

[edit]Methods of extraction

Sunflower oil can be extracted using chemical solvents, or squeezed directly from sunflower seeds by crushing them in an expeller press. Cold pressing sunflower oil using an expeller press under low-temperature conditions is a preferred method for those seeking an extraction process that doesn't involve chemical solvents, as well as for people following a raw foods diet.

[edit]Refined versus unrefined

Refining sunflower oil through solvent extraction, degumming, neutralization and bleaching can make it more stable and suitable for high-temperature cooking, but will also remove some of the oil's nutrients and flavor, including color pigments, free fatty acids, phospholipids, polyphenols and phytosterols. Unrefined sunflower oil is less heat stable, but will retain more of its original nutrient content and flavor, and is well suited to dishes that require low- or no-heat.

Palm oil

2012-07-21T01:58:00.003-07:00

Palm oil is an edible plant oil and is derived from the mesocarp of the fruit of the oil palm (Elaeis guineensis).^[1] It is not to be confused with palm kernel oil derived from the kernel of the same fruit,^[2] or coconut oil derived from the kernel of the coconut palm (Cocos nucifera). The differences are in color (raw palm kernel oil lacks carotenoids and is not red), and in saturated fat content: Palm mesocarp oil is 41% saturated, while Palm Kernel oil and Coconut oil are 81% and 86% saturated respectively ^[3]

Naturally reddish in color because of a high beta-carotene content, palm oil, along with coconut oil, is one of the few highly saturated vegetable fats. It is semi-solid at room temperatures and contains several saturated and unsaturated fats in the forms of glyceryl laurate (0.1%, saturated), myristate (1%, saturated), palmitate (44%, saturated), stearate (5%, saturated), oleate (39%, monounsaturated), linoleate (10%, polyunsaturated), and alpha-linolenate(0.3%, polyunsaturated).^[4] Like all vegetable oils, palm oil does not contain cholesterol,^[5]^[6] although saturated fat intake increases both LDL^[7] andHDL^[8] cholesterol.

Palm oil is a common cooking ingredient in the tropical belt of Africa, Southeast Asia and parts of Brazil. Its increasing use in the commercial food industry in other parts of the world is buoyed by its lower cost^[9] and the high oxidative stability (saturation) of the refined product when used for frying.^[10]^[11]

The use of palm oil in food products attracts the concern of environmental activist groups; the high oil yield of the trees have led, in parts of Indonesia, to removal of forestry in order to make space for oil-palm monoculture. This has resulted in acreage losses of the natural habitat of the orangutan.^[12]Consumer pressure could encourage palm oil companies to modify their practices. The Roundtable on Sustainable Palm Oil, an international non-profit association, that brings together conservation groups and palm-oil firms, says that it "will not certify oil grown on land that was deforested to farm the crop".^[13]

[edit]History

Oil palms (Elaeis guineensis)

Palm oil (from the African oil palm, Elaeis guineensis) has long been recognized in West African countries, and is widely used as a cooking oil. European merchants trading with West Africa occasionally purchased palm oil for use as a cooking oil in Europe, but palm oil was not able to supplant olive oil or butter, and culinary uses of palm oil remained rare outside West Africa until after commercial oil palm plantation development in non-African tropical regions. In the Asante Confederacy, state-owned slaves built large plantations of oil palm trees, while in the neighbouring Kingdom of Dahomey, King Ghezopassed a law in 1856 forbidding his subjects from cutting down oil palms.

Palm oil became a highly sought-after commodity by British traders, for use as an industrial lubricant for machinery during Britain's Industrial Revolution.^[14]Palm oil formed the basis of soap products, such as Lever Brothers' (now Unilever) "Sunlight" soap, and the American Palmolive brand.^[15] By around 1870, palm oil constituted the primary export of some West African countries, such as Ghana and Nigeria, although this was overtaken by cocoa in the 1880s.^{[citation needed]}

[edit]Research

In the 1960s, research and development (R&D) in oil palm breeding began to expand after Malaysia's Department of Agriculture established an exchange program with West African economies and four private plantations formed the Oil Palm Genetics Laboratory.^[16] The government also established Kolej Serdang, which became the Universiti Pertanian Malaysia (UPM) in the 1970s to train agricultural and agro-industrial engineers and agro-business graduates to conduct research in the field.

In 1979, following strong lobbying from oil palm planters and support from the Malaysian Agricultural Research and Development Institute (MARDI) and UPM, the government set up the Palm Oil Research Institute of Malaysia (Porim).^[17] B.C. Sekhar was instrumental in helping Porim recruit and train scientists to undertake R&D in oil palm tree breeding, palm oil nutrition and potentialoleochemical use. Sekhar, as founder and chairman, pushed Porim to be a public-and-private-coordinated institution. As a result, Porim (renamed Malaysian Palm Oil Board in 2000) became Malaysia's top research entity commercializing 20% of its innovations, compared to 5% among local universities.^{[citation needed]}

[edit]Nutrition

Further information: palmitic acid

Many processed foods contain palm oil as an ingredient.^[18]

Palm oil is composed of fatty acids, esterified with glycerol just like any ordinary fat. It is high in saturated fatty acids. Palm oil gives its name to the 16-carbon saturated fatty acid palmitic acid. Monounsaturated oleic acid is also a constituent of palm oil. Unrefined palm oil is a large natural source of tocotrienol, part of the vitamin E family.^[19]

The approximate concentration of fatty acids in palm oil is:^[20]

Fatty acid content of palm oil
Type of fatty acid			pct
Myristic saturated C14			1.0%
Palmitic saturated C16			43.5%
Stearic saturated C18			4.3%
Oleic monounsaturated C18			36.6%
Linoleic polyunsaturated C18			9.1%
Other/Unknown			5.5%
red: Saturated; orange: Monounsaturated; blue: Polyunsaturated

[edit]Red palm oil

Red palm oil gets its name from its characteristic dark red color, which comes from carotenes, such as alpha-carotene, beta-carotene and lycopene, the same nutrients that give tomatoes, carrots and other fruits and vegetables their rich colors.

Red palm oil contains at least 10 other carotenes, along with tocopherols and tocotrienols (members of the vitamin E family), CoQ10, phytosterols, and glycolipids.^[21] In a 2007 animal study, South African scientists found consumption of red palm oil significantly decreased p38-MAPK phosphorylation in rat hearts subjected to a high-cholesterol diet.^[22]

Since the mid-1990s, red palm oil has been cold-pressed and bottled for use as cooking oil, and blended into mayonnaise and salad oil.^[23] Red palm oil antioxidants like tocotrienols and carotenes are added to foods and cosmetics because of their purported health benefits.^[24]^[25]^[26]

In a 2004 joint study between the Kuwait Institute for Scientific Research and the Malaysian Palm Oil Board, the scientists found cookies, being higher in fat content than bread, are a better vehicle for red palm oil phytonutrients.^[27]

In a 2009 study, scientists in Spain tested the acrolein emission rates from the deep-frying of potatoes in red palm, olive and polyunsaturated oils. They found higher acrolein emission rates from the polyunsaturated oils. The scientists characterized red palm oil as "mono-unsaturated".^[28]

Frying French fries in red palm oil gives them an attractive color.^[29]

[edit]Refined, bleached, deodorized palm oil

Palm oil products are made using milling and refining processes: first using fractionation, with crystallization and separation processes to obtain solid (stearin), and liquid (olein) fractions. Then melting and degumming removes impurities. Then the oil is filtered and bleached. Next, physical refining removes smells and coloration, to produce "refined bleached deodorized palm oil", or RBDPO, and free sheer fatty acids, which are used as an important raw material in the manufacture of soaps, washing powder and other hygiene and personal care products. RBDPO is the basic oil product sold on the world's commodity markets, although many companies fractionate it further into palm olein, for cooking oil or other products.^[30]

Splitting of oils and fats by hydrolysis, or under basic conditions saponification, yields fatty acids, with glycerin (glycerol) as a byproduct. The split-off fatty acids are a mixture ranging in carbon chain length from C4 to C18, depending on the type of oil or fat.^[31]^[32]

[edit]Uses

Derivatives of palmitic acid were used in combination with naphtha during World War II to produce napalm (aluminum naphthenate and aluminum palmitate).^[33]

Many processed foods contain palm oil as an ingredient.^[18] The highly saturated nature of palm oil, while undesirable from the health perspective, renders it solid at room temperature in temperate regions, making it a cheap substitute for butter in uses where solid fat is desirable, such as the making of pastry dough and baked goods: in this respect, it is less of a health-hazard than the alternative substitute of partially hydrogenated trans fat.

[edit]Biodiesel

Main article: Biodiesel

Palm oil, like other vegetable oils, can be used to create biodiesel, as either a simply processed palm oil mixed with petrodiesel, or processed through transesterification to create a palm oilmethyl ester blend, which meets the international EN 14214 specification. Glycerin is a byproduct of transesterification. The actual process used to produce biodiesel around the world varies between countries and the requirements of different markets. Next-generation biofuel production processes are also being tested in relatively small trial quantities.

The IEA predicts biofuels usage in Asian countries will remain modest. But as a major producer of palm oil, the Malaysian government is encouraging the production of biofuel feedstock and the building of palm oil biodiesel plants. Domestically, Malaysia is preparing to change from diesel to biofuels by 2008, including drafting legislation that will make the switch mandatory.

Palm oil

2012-07-21T01:58:00.001-07:00

[edit]History

Oil palms (Elaeis guineensis)

[edit]Research

[edit]Nutrition

Further information: palmitic acid

Many processed foods contain palm oil as an ingredient.^[18]

The approximate concentration of fatty acids in palm oil is:^[20]

Fatty acid content of palm oil
Type of fatty acid			pct
Myristic saturated C14			1.0%
Palmitic saturated C16			43.5%
Stearic saturated C18			4.3%
Oleic monounsaturated C18			36.6%
Linoleic polyunsaturated C18			9.1%
Other/Unknown			5.5%
red: Saturated; orange: Monounsaturated; blue: Polyunsaturated

[edit]Red palm oil

Frying French fries in red palm oil gives them an attractive color.^[29]

[edit]Refined, bleached, deodorized palm oil

[edit]Uses

Derivatives of palmitic acid were used in combination with naphtha during World War II to produce napalm (aluminum naphthenate and aluminum palmitate).^[33]

[edit]Biodiesel

Main article: Biodiesel

Coronary heart disease and lipoproteins

2012-07-21T01:57:00.001-07:00

Coronary Heart Disease (CHD), characterized by a limited supply of oxygen to the heart muscle, has clinical manifestations ranging from angina pectoris to myocardial infarction (MI) and sudden death. The primary cause of CHD is coronary atherosclerosis (ATS), due to lipid-rich lesions in the intima of the coronary arteries. These begin in early life as "fatty streaks" and later form fibrous, often calcified and ulcerated, lesions that narrow the arterial lumen. A thrombus, superimposed on the lesions, may precipitate MI and sudden death. These events depend upon the atherosclerotic lesion and a complex interplay of haemostatic factors. While the mechanisms are only beginning to be elucidated, it is apparent that the processes leading to CHD involve the development of ATS, thrombosis and vascular reactivity as well as their interrelationships.

Epidemiology and experimental evidence

Since the 1940s and 1950s, studies within populations as well as cross- cultural comparisons produced abundant evidence that higher serum cholesterol levels are associated with increased risk of CHD (Levy et al., 1979; Anderson, Castelli and Levy, 1987; Committee on Diet and Health, 1989; Pooling Project, 1978). Recent studies, such as the Multiple Risk Factor Intervention Trial (Stamler, Wentworth and Neston, 1986) in the USA showed a continuous, graded, statistically significant association between baseline serum cholesterol and six-year, age-adjusted CHD death rates for both hypertensive and normotensive individuals and for both smokers and non-smokers. A threshold level, below which an increase in serum cholesterol has no effect on risk, could not be identified. Similarly, in a Chinese population with generally low serum cholesterol levels, a statistically significant relationship between serum cholesterol and CHD mortality was found (Chen, et al., 1991) indicating that any increase in serum cholesterol increases risk of CHD. Cross-country studies, such as the Seven Countries Study (Keys et al., 1986; Keys, 1970) also showed a graded increase in risk of CHD as serum cholesterol levels rise. These associations between serum cholesterol levels are primarily related to levels of low density lipoprotein (LDL), the primary carrier of cholesterol in the serum.

Associations between diet, serum cholesterol levels and risk of CHD have been welldocumented in cross-country comparisons (Keys et al., 1986; Levy et al., 1979; Committee on Diet and Health, 1989; Lewis et al., 1978). Populations with relatively high intakes of fat, especially animal fat and cholesterol, have relatively high serum cholesterol levels and high mortality rates from CHD when compared with populations consuming low-fat diets.

Numerous studies on people who immigrated from low-risk to high-risk populations (Nichaman et al., 1975; Halfon et al., 1982; Kato et al., 1973) demonstrated that environmental factors rather than genetic susceptibility led to these differences and that diet consistently played a primary role. Generally, these high-risk populations consume diets of affluent societies. It is recognized that these populations differ from low-risk populations in many ways. For example, diets of low risk populations are not only low in fat, they are commonly higher in dietary fibre and other components of plant origin. Also, individuals in such societies are less sedentary. Abundant experimental data, however, in both animals and humans confirm that there is a primary role for dietary fat and cholesterol in the control of serum lipid levels.

Comparisons of diet and serum cholesterol levels within population groups where diet is relatively homogeneous, may or may not show a correlation between dietary fat consumption and serum cholesterol levels (Morris, Marr and Clayton, 1977; Garcia-Palmieri et al., 1980; Jacobs, Anderson and Blackburn, 1979). It is well-known that individuals vary greatly in serum cholesterol level, even when diet is constant (Keys, Anderson and Grande, 1959) and there are "hyper- and hyporesponders" when dietary fat and cholesterol are modified (Katan and Beynen, 1987; Katan et al., 1988). In addition, the methods for estimating the intake and composition of food consumed by individuals are severely limited and often unreliable (Jacobs, Anderson and Blackburn, 1979; Livingstone et al., 1990; Schoeller, 1990; Black et al., 1993). Hence, it is not surprising that some studies within a population show little association between serum lipids and estimates of the fat in the diet. Intervention studies in which diet can be controlled demonstrate that marked changes in serum lipids can be induced by changes in fat and cholesterol intake, thus, they are consistent with the epidemiological findings.

Dietary fat and serum lipids

Many studies have demonstrated that the amount and composition of dietary fat are primary determinants of serum cholesterol levels and LDL. It has been concluded that, relative to carbohydrates, the saturated fatty acids elevate serum cholesterol, while the polyunsaturated fatty acids (linoleic acid) lower serum cholesterol, and the monounsaturated fatty acid (oleic acid) has no statistically significant effect (Keys, Anderson and Grande, 1957; Hegsted et al., 1965). While some studies over the past 30 years have yielded various results, on balance the current data (Hegsted et al., 1993) confirm these general conclusions as to the relative effects of saturated, polyunsaturated and monounsaturated fatty acids upon serum cholesterol levels. The specific potency of the saturated and polyunsaturated fatty acids to modify serum lipid levels has not been, and probably cannot be, clearly defined for all conditions. Originally, Keys and his colleagues (1957) thought the combined saturated fatty acids were twice as potent in elevating serum cholesterol as the polyunsaturated fatty acids were in lowering it; later studies led by Hegsted (1965) attributed greater potency to the polyunsaturates. However, individual studies conducted with few subjects and diets may show substantial differences in the effects observed. Combined analyses (Mensink and Katan, 1992; Hegsted et al., 1993) agree that the cholesterol-lowering effect of linoleic acid is 2 to 3 times less than the cholesterol-raising effect of saturates. However, they indicate substantial differences in relative potency depending upon the data selected for analysis. Whether this is due to the traits of individuals, diet characteristics or fats studied, the quality of specific studies, and so forth, is uncertain. It is clear that the amount of dietary fat and its composition are major determinants of serum cholesterol levels; that saturated fatty acids and dietary cholesterol elevate serum cholesterol and that polyunsaturated fatty acids (linoleic acid) have a modest cholesterollowering effect relative to carbohydrates.

Specific fatty acids and cholesterol

Saturated fatty acids. Early studies (Keys, Anderson and Grande, 1965; Hegsted et al., 1965) suggested that various saturated fatty acids have different effects upon serum cholesterol levels. Particular fats with high levels of stearic acid did not appear to be as hypercholesterolemic as expected from their content of saturated fatty acids. These differences were investigated by the use of transesterified fats, incorporating lauric, myristic, palmitic and stearic acid into olive and safflower oil (McGandy, Hegsted and Myers, 1970). Many of these preparations appeared to be approximately equal in their cholesterol-raising ability, thus suggesting that the position of the fatty acids in the triacylglyceride may be important as well. More recent data (Bonanome and Grundy, 1988) also indicated that stearic acid may not elevate serum cholesterol levels appreciably. Overall, the data indicate that stearic acid in most natural fats has minimal effects upon serum cholesterol levels. It should be specifically noted, however, that the effects of stearic acid and other saturated fatty acids on susceptibility to hypertension, cancer, obesity, and other illnesses, are unknown. Also, data on the activity of saturated fatty acids with regard to thrombotic activity are inadequate. Hence, whether it is desirable to substitute stearate for other fatty acids in the diet is still uncertain.

There is still considerable disagreement about the relative activity of the other saturated fatty acids - lauric, myristic and palmitic. The early data (Hegsted et al., 1965) suggesting that myristic acid was the most hypercholesterolemic of the saturated fatty acids may be due to the designs of the studies. Butterfat and coconut oil, both sources of myristic acid, were the primary saturated fats studied and the intake of total saturated fatty acids correlated with myristic acid intake. A direct comparison of myristic and palmitic acid showed that both raise LDL cholesterol relative to oleic acid, but that myristic acid was slightly more powerful (Zock, 1994). Most other metabolic and epidemiologic studies have not reported the intake of the specific saturated fatty acids (Denke and Grundy, 1992; Doherty and Iacono, 1992; Sundram, Hayes and Siru, 1994). Some animal and human studies (Hayes et al., 1991; Ng et al., 1991) have reported minimal effects of palmitic acid but this may be due to the specific diets utilized (Hayes et al., 1991; Pronczuk, Khosla and Hayes, 1994). In studies of cebus monkeys, it was reported that palmitic acid is only hypercholesterolemic when the cholesterol intake is high (Khosla and Hayes, 1993), however, metabolic studies in normolipidemic volunteers showed that palmitic acid strongly raised total cholesterol (Bonanome, 1988; Denke, 1992; Zock, 1994). Palmitic acid is the major saturated fatty acid in most diets and lauric, myristic and palmitic acid are considered to be the principal hypercholesterolemic fatty acids although they may differ in potency. Recent findings on individual fatty acids are summarized in Figure 9.1.

Polyunsaturated fatty acids. Replacing saturated fatty acids by either oleic or linoleic acid lowers serum cholesterol levels. In many specific studies, it was not possible to determine whether it was the addition of oleic and/or linoleic acid or the lowering of intake of saturated fatty acids which caused the reduction in serum cholesterol. Predictive equations attribute the changes in serum cholesterol to changes in saturated and polyunsaturated fatty acids while the monounsaturated fatty acid (oleic) was shown to be neutral (Keys, Anderson and Grande, 1957; Hegsted et al., 1965; Mensink and Katan, 1992; Hegsted et al., 1993) or to have a small cholesterol-lowering effect (Mensink and Katan, 1992).

FIGURE 9.1 : Effects of individual dietary fatty acids on serum total and lipoprotein cholesterol

Interestingly, in several studies the linoleic acid content of adipose tissue which is probably a better indicator of usual, long-term, linoleic acid intake than dietary data (van Staveren et al., 1986), as well as the linoleic acid content of serum phospholipids or cholesterol esters, showed an inverse relationship between linoleic acid levels and the incidence of myocardial infarction (Wood et al., 1984; Logan et al., 1978; Valek et al., 1985; Riemersma et al., 1986). This may indicate a protective role of the polyunsaturated fatty acids other than their effect on serum lipid levels (Renaud et al., 1986). Studies with animals (Charnock et al., 1985; Charnock, Abeywardena and McLennon, 1986) indicate that the polyunsaturated fatty acids, especially the n-3 fatty acids, may protect against cardiac arrythmias.

EPA and DHA. In recent years, evidence that fish-consuming populations have a low prevalence of CHD has generated a great deal of interest in fish oils, which are major sources of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (Dyerberg et al., 1978).

Although the evidence is somewhat controversial, the consumption of such oils appears to have relatively little effect upon LDL and HDL levels but does appear to be effective in lowering serum triacylglycerols and very low-density lipoproteins (Leaf and Weber, 1988). The epidemiological data indicate that there is an apparent protective effect which is probably due to the effects on the thrombotic or immunologic mechanisms rather than effects upon serum lipoproteins. Much of the experimental data has dealt with diets in which fish oils were the major source of dietary fat and it is unlikely that results can be extrapolated to ordinary levels of consumption. This, of course, is not true of the epidemiological findings.

Dietary cholesterol. While it has long been apparent that dietary cholesterol elevated serum cholesterol, the shape of the dose-response curve has been debated. It is clear that the observed responses to changes in cholesterol intake are highly variable and may depend, in part, upon the nature of the dietary fat, cholesterol intake, and perhaps, other dietary constituents (Hopkins, 1992). Hence, as with changes in dietary fat, a good quantitative definition of the response expected from changes in cholesterol intake under all conditions is probably not possible.

It is relevant to note that in the hamster model (Spady and Dietschy, 1985; Woollett et al., 1992) the cholesterol-lowering activity of linoleic acid was clearly evident only when the LDL receptor was adequately suppressed by dietary cholesterol and/or saturated fat. This may explain, in part, the limited potency of linoleic acid which was reported when human subjects were fed formula diets which were low in cholesterol (Hegsted and Nicolosi, 1990).

Intervention teals. Intervention trials generally confirm the effects of dietary fat and cholesterol although the changes observed are often less than in metabolic trials in which better dietary control is possible. For example, a significant drop in serum cholesterol was found when a diet which was low in animal fat and high in polyunsaturated fat was substituted for the usual Finnish diet (Ehnholm et al., 1982) which is high in saturated fat and cholesterol. In southern Italy, the reverse type of study, in which animal fat was substituted for olive oil and carbohydrate, resulted in a substantial rise in serum cholesterol and LDL (Ferro-Luzzi et al., 1984). Relatively small changes in serum lipids have been observed in some field trials (Hunninghake e, al., 1993) undoubtedly due to the difficulties in obtaining adequate food consumption data and good dietary compliance in large trials. The Finnish Mental Hospital Study (Turpeinen et al., 1979) reported a significant decrease in CHD in individuals who were fed a diet higher in polyunsaturated fatty acids. When the results of a number of trials, many of which included drugs to lower cholesterol, were summarized (Committee on Diet and Health, 1989; Smith, Song and Sheldon, 1993) the findings were varied but consistent: diet can have a desirable effect in lowering serum cholesterol. Several studies (Blankenhorn et al., 1987; Ornish et al., 1990; Schuler et al., 1992) demonstrated that a severely restricted diet can limit or actually reverse the development of atherosclerotic lesions.

Such immediate effects of dietary modification upon lesion development appear to be consistent with change in the diets of populations, such as those observed in some European countries during World War II (Schettler, 1979). Large decreases in mortality from CHD in some countries have been observed in recent years. They were greater in countries such as the USA and Australia which emphasized dietary modification in the general population (Dwyer and Hetzel, 1980). Overall, the data from field trials support the epidemiologic and metabolic conclusions about the desirability of dietary modifications to lower serum cholesterol levels (Stamler et al., 1993).

Dietary effects on lipoproteins

Low density lipoproteins (LDL) carry most cholesterol and are identified as the most important cause of atherosclerosis. The dietary effects of the various fatty acids and cholesterol upon LDL levels generally parallel those described above for total serum cholesterol (Mensink and Katan, 1992; Hegsted et al., 1993). The saturated fatty acids, presumably lauric, myristic and palmitic acids, elevate LDL levels; linoleic acid lowers LDL levels; and oleic acid appears to be neutral or slightly lowers it relative to carbohydrates. It has recently been suggested that oxidized LDL is the major, perhaps the cause, of atherosclerosis. Oxidized LDL is more readily taken up by the monocytes which leads to the atherosclerotic plaque.

Some studies suggest that various antioxidants limit the development of atherosclerosis in animals and humans (Steinberg et al., 1989; Frei, England and Ames, 1989; Jialal, Vega and Grundy, 1990; Riemersma et al., 1991). Vitamin E, carotenoids and vitamin C have received the most attention but other antioxidants may be effective as well (Bjorkhem et al., 1991). High intakes of vitamin E have been associated with reduced risk of coronary heart disease in both men (Rimm et al., 1993) and women (Stampfer et al., 1993). Hence, the intake and circulating levels of these and perhaps other antioxidants must be considered in assessing the relative risk of disease. Presumably, this will become more important as this field develops. Insufficient evidence is available to indicate the relative importance of the circulating levels of LDL compared to the levels of antioxidants. This does not detract from the convincing evidence that high levels of LDL constitute a major risk of CHD.

Within populations, high levels of high density lipoproteins (HDL) are strongly associated with reduced risk of CHD (Wilson, Abbott and Castelli, 1988; Gordon and Rifkind, 1989; Gordon et al., 1989; Knuiman et al., 1987). HDL is thought to actively protect against CHD (NIH Consensus, 1993) presumably by reverse cholesterol transport, that is, transport from the periphery to the liver although this is uncertain in humans. Within populations, the level of HDL is determined partly by genetic factors and partly by environmental conditions. HDL levels are lowered by smoking, obesity and male hormones, and are raised by physical activity as well as by consumption of alcohol, saturated fats and cholesterol. However, the increase in HDL which is attributable to saturated fats and cholesterol is outweighed by greater increases in LDL. Evidence that manipulation of HDL levels, by dietary or other means, modifies susceptibility to CHD is unavailable and the significance of dietary-induced changes in HDL levels needs to be clarified. Summaries of the current data (Mensink and Katan, 1992; Hegsted et al., 1993) indicate that all three classes of fatty acids tend to elevate HDL levels, with saturated fatty acids being the most potent and linoleic acids being the least influential. On the other hand, low-fat diets which are known to protect against CHD also lower HDL levels (Denke and Breslow, 1988). After HDL is reduced by a low-fat diet, its metabolism is modified (Brinton, Eisenberg and Breslow, 1990). However, there is little reason to believe that dietary modifications which reduce LDL levels are undesirable although they may also reduce HDL levels to some extent.

Trans fatty acids

The effects of trans fatty acids have been discussed elsewhere in this report. Available data indicate that the serum lipoprotein responses to monounsaturated trans fatty acids approximate the effects of saturated fatty acids. Whether they have specific effects on HDL, as indicated by the studies of Mensink and Katan (1990), or not (Judd et al., 1994) is a question which remains to be clarified.

Conclusion

Abundant evidence supports the conclusion that elevated levels of serum cholesterol and LDL constitute a major risk of atherosclerosis and coronary heart disease. The degree of risk may be modified by various antioxidants and complex interactions between the degree of atherosclerosis, thrombotic and fibrolytic, and vascular reactivity.

When various fats are fed to human beings under controlled conditions, differences in chain length and the number and geometry of the double bonds of the fatty acids induce marked differences in the concentration of lipids and lipoproteins in fasting blood serum. Relative to carbohydrate, the saturated fatty acids - lauric, myristic and palmitic - raise both LDL and HDL cholesterol and lower VLDL cholesterol and triglycerides. In most fats, stearic acid appears to have minor effects. Linoleic acid lowers LDL while oleic acid appears to be neutral. Oleic and linoleic acids may elevate HDL levels modestly relative to carbohydrates with linoleic acid having the least effect. Trans isomers of oleic acid elevate LDL levels and may depress HDL levels while the effects on other lipoproteins are, as yet, uncertain. The fatty acids of fish oils lower serum triglycerides markedly but appear to have little effect upon LDL and HDL levels. Dietary cholesterol also elevates LDL levels and probably HDL.

In general, the metabolic studies on the dietary effects of fats and cholesterol upon serum lipids and lipoproteins are consistent with epidemiologic and intervention studies and the trends over time observed in various populations. Each type of study concludes that dietary modifications that lower serum cholesterol and LDL levels decrease the risk of CHD.

Health, obesity and energy values of dietary fat

2012-07-21T01:56:00.005-07:00

Overweight is defined as an increase above a standard in body weight related to height. It is often measured by the Quetelet or Body Mass Index (BMI) which is weight in kilograms divided by the square of stature in metres (BMI = weight/height2). Obesity is also defined as an abnormally high percentage of body fat. In males, normal body fat represents 12-20 percent of body weight. Body fat represents 20-30 percent of body weight in normal females.

Weight standards for a population can be established by dividing a large sample of the population according to the normal distribution of their body weights in relation to height. The inherent difficulty with this approach is that there is an underlying assumption that average weights are healthy weights. An alternative approach to determining standards for healthy weights is to use body weights which are associated with the lowest overall risk to health. In several prospective studies, the lowest death rate was associated with a BMI close to 22 (Manson et al., 1987; Garrison and Kannel, 1993).

Longitudinal tracking of weight. Several epidemiological studies have examined the weight status of various populations over time (Noppa and Hallstrom, 1981; Borkan et al., 1986; Williamson et al., 1990) and they show a progressive rise in BMI in most populations. However, the weight status of an individual from infancy and childhood through adolescence and into adult life often follows an uneven track. (Bradden et al., 1986; Charney et al., 1976; Khouryet all, 1983; Mossberg, 1989; Zacketal., 1979).

A few studies (Garn et al., 1986; Johnston and Mack, 1978; Melbin and Vuille, 1976) have calculated the relative risk of being in the top weight category as an adult based on weight status in childhood or adolescence. When the lightest youngsters were compared with the heaviest ones, the heaviest youngsters were 1.6 to 2.5 times more likely to be overweight as adults. However, the Harvard Longitudinal Studies of Child Health and Development 50 year investigation found that the BMI of females during childhood had essentially no correlation with their BMIs when they reached middle-age (Casey et al., 1992). There was a better correlation between the BMIs of adolescent females and those of women at age 50 years, although this was still low. In females, the failure to show an effect of overweight in adolescence on mortality in adults may be due to this low correlation. In men, on the other hand, the correlation of BMI in childhood or adolescence with BMI at age 50 years was better, but the tracking of childhood and adolescent weight into adult life is still of a low order (Borkan et al., 1986).

Children from families where one or both parents are overweight are at higher risk of adult obesity. If these children are notably obese during their school years, a preventive programme may be advisable. Thus, ongoing surveillance of children and adolescents will help identify those who are at risk and may be helped by preventive service.

Health risks associated with obesity

Overweight and fat distribution are useful predictors of premature mortality and the risks of heart disease, hypertension, non-insulin-dependent diabetes mellitus, gallbladder disease and some cancers. However, if body fat per se were the major risk factor associated with premature mortality, obese women might be expected to have shorter life expectancies than obese men. This is generally not the case, and it is now recognized that it is fat distribution, especially an increase in abdominal and visceral fat, that is a predictor of the health risk related to obesity. For example, weight gain of less than 5 kg in women during adult life may carry little extra risk, particularly if the added weight is located in the femoral region. For most men, any weight gain after the age of 20 years increases risk because this fat is usually deposited as abdominal and visceral fat.

In epidemiology, the relationship between data on BMI and a given disease risk is shown to be curvilinear and this curve is often described as J- or U- shaped. This means that mortality and morbidity tend to increase as the BMI increases above 25 or drops below 18.5.

Life insurance statistics from the United States show that excess weight is associated with higher mortality rates. Based on 1979 data (Society of Actuaries and Association of Life Insurance and Medical Directors of America, 1980), a body weight which is 10 percent above average weight is accompanied by an 11 percent increase in excess mortality for men and a 7 percent increase for women. If body weight is 20 percent above average, the excess mortality rises to 20 percent for men and 10 percent for women. Conversely, the minimum mortality rates for both men and women occur among individuals who are approximately 10 percent below average weight.

More than six studies have been published showing that central adiposity is positively correlated with increased mortality as well as the risk for developing cardiovascular disease, diabetes mellitus and stroke (Lapidus et al., 1984; Larsson et al., 1984; Donahue et al., 1987; Ducimetiere, Richard and Cambien, 1986; Stokes, Garrison and Kannel, 1985). Among the highest quintile for central body fat, the relative risk of myocardial infarction was 8.2 times higher than that for the lowest quintile. For stroke and mortality in general, the relative risk was 3.8 and 2.8 times higher for individuals in the highest quintile compared to those in the lowest quintile.

Losing and regaining weight, so-called weight cycling, may also be hazardous. Data from the Chicago Gas and Electric Company Study (Hamm, Shekelle and Stamler, 1989) showed that those people who gained and lost weight had a significantly higher risk of death from cardiovascular disease than the group of individuals with no change in weight. More recently, data from the Framingham study were used to show that significant changes in weight were associated with a higher likelihood of mortality (Lissner et al., 1991). Caution . in interpreting data on weight cycling as a cause of detrimental changes is urged.

Obesity must modify some intermediate mechanism such as cardiac function, the metabolism of lipids or glucose to produce death or disease. However, even though severe overweight generally increases the risk of death, especially sudden death, in many studies it could not be seen as an independent variable. Two major problems plague the interpretation of studies in terms of obesity as an independent factor (Manson et al., 1987). First, many studies fail to separate smokers from non-smokers. Since smokers as a group tend to have lower body weights and higher mortality rates, including them in a study population influences the death rates and confounds the assignment of effects to body weight per se. Second, early mortality may bias the interpretation of weight status on life expectancy. For example, individuals who have lost or are losing weight at the time of an initial survey may die and thus overemphasise the effect of low body weights as a cause of higher mortality. The failure to identify obesity as an independent risk factor has led many to suggest that it is unimportant.

Diabetes mellitus. More than 90 percent of all diabetics have non-insulin dependent diabetes mellitus (NIDDM), and excessive weight gain and overweight are the major nutritional factors which increase the risk of developing NIDDM. The importance of body weight is demonstrated by the low level of NIDDM during World War II and during periods of famine. NIDDM is almost non-existent in individuals with a BMI of 20 or less. A BMI of 35 has an 8-fold increase in risk of NIDDM when compared with a BMI of 25.

Other types of diabetes mellitus are insulin-dependent (IDDM), gestational diabetes and a very rare form, malnutrition-related diabetes mellitus. IDDM is an immunologic disease which destroys the insulin-producing cells. Patients with this disease require insulin for survival. The nature of the autoimmune stimulus to pancreatic destruction is unknown. The role of diet in the development of this disease is not established.

The San Luis Valley study in the USA provided some evidence to support the hypothesis that a high fat, low-carbohydrate diet increases the risk for onset of non-insulin-dependent diabetes (Marshall, Hamman and Baxter, 1991). This involved cross-sectional analyses of individuals without a prior history of diabetes. A 24-hour diet recall preceded a glucose tolerance test. A high intake of fat appeared to be associated with impaired glucose tolerance, however, this may be the result of weight gain.

Other evidence comes from groups who changed their dietary patterns. These studies suggest that higher intakes of dietary fat and/or the weight gain which is associated with such increases, may be a factor in the onset of non-insulin-dependent diabetes. The Australian Aborigines were prone to the disease when they made a transitio,n from their traditional manner of living to an urban life-style (O'Dea, White and Sinclair, 1988). The mild elevation in plasma triglycerides and fasting insulin levels were consistent with insulin resistance. A group of Bangladeshis who had emigrated to the UK were found to have low plasma cholesterol concentrations, enhanced insulin resistance and three times the usual prevalence of diabetes, as well as a high rate of morbidity and mortality from coronary heart disease (McKeigue et al., 1988). A deterioration in carbohydrate tolerance and changes in lipoprotein patterns of the Pima Indians and Caucasians also point toward problems with the modern, high fat diet and obesity (Swinburn et al., 1991).

Ethnic differences in the C-peptide response relative to the insulin response in testing for glucose tolerance led to the tentative conclusion that dietary fat may be involved in determining insulin secretion and its clearance in the liver (Cruickshank et al., 1991). There is still more speculation than evidence to link dietary fat with non-insulin-dependent diabetes. At the present time, the general rationale for modifying dietary fat intakes has been to reduce the risk of coronary heart disease in diabetics.

Causes of obesity

Nutrient balance of fat storage. Obesity is always a chronic failure to balance nutrient intakes with expenditure (oxidation) (Bray, York and Fisler, 1989). There are various causes of obesity. At one extreme, obesity may be due simply to excess food (energy) intake in relation to energy requirements. In these cases, factors of heredity play an important role in the genesis of obesity which can develop even when the diet is composed primarily of carbohydrates. At the other extreme, there are those types of obesity where dietary composition, particularly a high fat intake, is central to its development. Any of these types of dietary obesity can be controlled by changing the composition of diets, by restraining the intake of food, or by increasing nutrient oxidation.

While overall energy balance is central to obesity, the concept of macronutrient balance is also useful for understanding the factors affecting excess weight gain and loss. In a normal adult, the daily energy intake from carbohydrates would be between 50 and 100 percent of the total carbohydrate stores, in the body. In contrast, the protein intake would be a little over 1 percent of total stores while the fat intake would be considerably less than 1 percent of that stored in the body. Glycogen (the storage form of carbohydrate) metabolism is closely regulated and, depending on the balance between carbohydrate intake and oxidation, there can be wide fluctuations in the carbohydrate stores over even short periods of time. This is not the case with protein and fat stores for which it takes considerably longer to affect appreciable change.

The process of regulating nutrient balance is complex. The feedback model for nutrient balance is described as having four components (Bray, 1987). The first is the "controlled system" which consists of the intake, digestion, absorption, storage and metabolism of the nutrients in food. The second is the "controller" located in the brain, and the third is comprised of the feedback signals which tell the controller about the state of the controlled system. Pinally, there are the mechanisms that modulate nutrient intake and energy expenditure.

In general, there are effective feedback and control mechanisms for regulating and balancing carbohydrate intake and oxidation (Flats, 1988). It is more difficult to become obese by eating a very high carbohydrate diet than by eating a high fat diet for a number of reasons. First, the quantity (volume) of high carbohydrate/high fibre foods which is required is much larger than that needed with a high fat diet. Second, the storage capacity for carbohydrates is limited. Third, the biochemical pathways for conversion of carbohydrate to fat are limiting and energetically expensive and are virtually negligible under normal dietary conditions in humans. Finally, the intake of carbohydrate stimulates carbohydrate oxidation so that carbohydrate balance is maintained once glycogen stores are filled, a process also stimulated by carbohydrate consumption.

Protein balance is also well-controlled. Protein stores rise gradually and only in response to stimuli other than increased protein intake. Protein which is consumed in excess of what is needed for tissue building and repair as well as enzyme formation, is converted to carbohydrate. Positive protein balance can contribute to overall energy balance in the same way that positive carbohydrate balance does.

Chronic imbalance between fat intake and fat oxidation can lead to changes in fat stores of adipose tissues. Avoiding storage of the fat consumed in a high fat diet requires that the dietary fats be oxidized. In clinical studies low rates of fat oxidation in the basal state predict an increase in body weight (Zurlo et al., 1990). It is only when the oxidation of fat equals the intake of fat that a stable body weight can be achieved.

While carbohydrate and protein oxidation are affected by carbohydrate and protein consumption, fat oxidation is not affected by fat intake and the day-to-day relationship between fat balance and fat intake is weak (Flats, 1988). Fat oxidation is related most strongly to energy balance (with a negative energy balance promoting fat oxidation) and also to the degree of body fat (Schulz et al., 1992; Zurlo et al., 1990). Creating a negative energy balance through exercise or dietary restriction can effectively increase fat oxidation, as can reducing the fat content of the diet. However, as weight is lost, fat oxidation also tends to decline. To prevent an individual from regaining weight which has been lost, the intake of fat must be reduced by approximately 20 g/day for each 10 kg of fat lost (Schulz et al., 1992).

There are major differences between individuals in their capacity to increase the oxidation of fat after beginning a high fat diet (Zurlo et al., 1990). While much of this difference is genetic, physical training can increase oxidation of fatty acids by muscle and reduce the tendency to gain weight. For this reason, adequate physical activity should be part of any weight control programme.

Some papers have shown a weak positive correlation between fat intake and body weight (WHO, 1990; Romieu et al., 1988, Miller et al., 1990) but others have not. Access to a diet with more than 30 percent energy from fat produces obesity in many animals. It was found that women who have lowered fat intakes have reduced body weight providing further evidence of a positive association between fat intake and body weight. However, in longer trials the effect has been small, probably because compliance during long studies fails (Sheppard, Kristal and Kushi, 1991; Lissner et al., 1991, Lee-Han et al., 1988).

Diet Caloric Density. It is well-recognized that energy per 100 grams of diet, referred to as caloric density, increases as fat content rises. Low-fat diets have resulted in weight loss in short-term studies, however, in long-term trials, low-fat diets in premenopausal women resulted in the consumption of an additional 19 percent of energy to maintain weight (Prewitt, 1991). The real long-term change is unknown because food was supplied to the subjects in these studies. In free-living persons, reinforcement and motivation are needed for adherence to a low-fat diet.

From the data available, it is clear that obesity is a chronic problem for which the cure is very elusive. Weight loss usually occurs during effective treatment; however, when treatment is terminated weight regain is common. This is consistent with the course of most chronic problems, and clearly indicates that prevention is the preferred method of controlling obesity.

Energy values of fat

Fatty acids are the dietary components that account for the highest amount of energy liberated during oxidation of lipids. Glycerol, to which most fatty acids are esterified, is a 3-carbon molecule with 3 oxygen atoms. Although glycerol is 10 percent by weight of triacylglycerol, it accounts for only 5 percent of the energy. The fatty acids of food impart the high energy value that is of nutritional interest.

The traditional factor for calculating the amount of dietary fat is 9 kcal (37.7 kj)/g compared to 4 kcal (16.7 kj)/g for carbohydrate and protein (FAO/WHO, 1978). Onginally these values were proposed by Atwater, and are based on the amounts of energy liberated when these macronutrients are metabolically oxidized, allowing for incomplete intestinal absorption.

The factor of 8.37 has been used for many decades to convert grams of fat in cereals, fruits and vegetables to calories (Merrill and Watt, l9SS). The precision in this 3-digit number is unwarranted, particularly upon examination of its derivation.

At the turn of the century, Atwater proposed factors for estimating the energy value of nutrients. The heat of combustion for triglycerides was applied to extracts of various foods, but for cereals, fruits and vegetables the "assumed or calculated" value was given as 9.30 calories per gram. Merrill and Watt (1955) copied this figure from a table created in 1900 by Atwater and Bryant. Merrill and Watt wrote: "For fat as it occurs in cereals and other plant sources Atwater assumed the apparent digestibility to be 90 percent and we have continued this practice. The energy factor for fat in plant foods is therefore, assumed to be 8.37 calories per gram."

Since Atwater had used a coefficient of digestibility of 95 percent for butter, it was assigned also to the separated fats of plant origin. The calculation for fats and oils as such became 95 percent of 9.30 or 8.84 calories per gram. These factors have a long history of many assumptions. The corrections for digestibility are inappropriate for the dietary oils and fats commonly consumed, and the factor of 9 for converting grams of all dietary fat to calories is more suitable and offers consistency.

Fat substitutes

Advice to reduce fat and energy consumption has led to the production of foods with a lower content of fat and to the development of fat substitutes. There are two principal approaches to the replacement of dietary fat. The first involves hydratable carbohydrates and proteins with the mouthfeel of fats. The second includes non-absorbed synthetic substances with the physical properties and technical function of fat within foods.

Protein and carbohydrate materials can be produced in forms that binds up to three times their weight in water and that create particles that imitate the mouthfeel of fat. When the hydrated material replaces fat in food, the caloric reduction is from 9 kcal/g to 1 to 2 kcal/g. The carbohydrates used are the low molecular weight starches, dextrins, maltodextrins and gums (xanthan for example), the proteins for fat replacers come primarily from milk and egg white. Since these substances have not been altered chemically, they are digested, absorbed and metabolized like ordinary nutrients (Vanderveen and Glinsmann, 1992).

The other group of fat substitutes, which has not yet reached the market, is produced by chemical synthesis from a wide range of possible structures having different digestibilities and effects on gastrointestinal function. Such material replaces fat on a gram to gram basis. The concern about some non-absorbable lipophilic substances such as fatty acid esters of sugars revolves around impaired absorption of fat-soluble compounds, both vitamins and drugs. For example, the prolonged use of sucrose polyester had a negative effect on the body stores of d-tocopherol (Jandacek, 1991). Individual assessments for safety are required for each type of synthesized fat substitute (Borzelleca, 1992; Vanderveen and Glinsmann, 1992).

The value of these kinds of materials for reducing either the total energy consumption, as an aid in the treatment or prevention of obesity, or as modifiers of a kind of dietary fat remains to be investigated. The assessment of fat substitutes must include the effect on the total diet and the redistribution of macro- and micronutrients (Rolls and Shide, 1992).

Extrapolation from animal studies may be inappropriate since human beings can choose replacements from a wide variety of foods.

Special attention must be given to the effect of fat substitutes on the consumption of micronutrients, such as vitamins A, D and E, since certain dietary fats are often important sources of these nutrients and the amount of dietary fat may be important in the utilization of such materials.

Conclusions

Obesity and excess visceral fat are conditions that predispose individuals to chronic diseases. Excess body fat is a major risk-factor of morbidity and mortality in most affluent countries and, increasingly, in many developing countries.

High intakes of dietary fat are associated with increasing levels of obesity in animals. For humans, the relationship between the rates of fat intake and oxidation is clear, however, the association between fat intake as a proportion of energy and obesity is weak.

Prevention of obesity involves early recognition and surveillance, regular physical activity and, for adults, a restrained pattern of eating.

Maternal nutrition

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Maternal nutrition

During pregnancy, the acquisition of long-chain polyunsaturated fatty acids for placental and fetal development is required. In addition, there is firm evidence that maternal nutrition and health in the periconceptional period is of crucial significance. Events prior to conception influence the long term physiological process of fat storage and the nature of the fat store. This is the fat which is available during the critical period of cell commitment and division during embryonic and placental development in the first trimester. Substantial amounts of fat are also stored from conception to provide for fetal growth in the third trimester and the initial needs of lactation.

The evidence from animal experiments suggests that pre and post-natal nutrition have pronounced effects on brain lipid composition and learning (Gall) and Socini, 1983). Specific deficits of n-3 fatty acids influence neural integrity (Budowski, Leighfield and Crawford, 1987) and selectively affect learning and visual abilities (Wheeler, Benolken and Anderson, 1975; Lamptey and Walker, 1976; Bourre et al., 1989; Yamamoto et al., 1987). Studies with non-human primates confirm that n-3 deficiency depresses the development of retinal function and visual acuity (Neuringer, Anderson and Connor, 1988; Connor, Lin and Neuringer, 1990).

Recent studies replicated these findings in human infants indicating the essentiality of n-3 fatty acids and the need for the inclusion of docosahexaenoic acid (DHA) in food for infants (Birch et al., 1992, 1993 a, b; Carlson et al., 1993 a, b, Uauy et al., 1990; Uauy, Birch and Birch, 1992). Although there are not similar studies for arachidonic acid, the experimental evidence indicates that low arachidonic acid levels are associated with low pre-natal (Crawford et al., 1989; Leaf et al., 1992) and post-natal growth in preterm infants (Carlson et al., 1992). Conditionally, arachidonic acid should be considered as an essential nutrient during early development because: it is present in human milk (Sas et al., 1986; Koletzko, Thiel and Abiodun, 1992) along with DHA; the interplay between the n-3 and n-6 families; the specifie functions of araehidonic acid in neural and vascular function; and the role of its eicosanoids in cell regulation.

There have not been the same kind of controlled, randomized trials for term infants as those performed for preterm ones. However, the preliminary studies comparing term infants who were breastfed with those fed low a -linolenic acid formula suggest that the term infant's brain may also be responsive to external nutritional influences (Birch et al., 1993 b; Gibson et al., 1993). Data on brain composition provide a comparison of formula-fed versus breastmilk-fed babies and give further evidence that dietary fatty acids influence the developing brain of term infants (Farquharson et al., 1992).

Preconceptional nutrition

Embryology and clinical studies provide evidence that the mother's nutritional status around the time of conception has greater significance in terms of birth weight (Caan et al., 1978; Villar and Riveria, 1988; Wynn et al., 1991), prevention of neural tube defects (Wald et al., 1991) and non-genetic congenital disorders (Wynn and Wynn, 1981) than nutritional status in the latter part of pregnancy. Poor maternal nutrition or metabolic status at this early stage represents a significant risk of compromising embryonic development, cell commitment and the rate of DNA replication in a manner which cannot be compensated later.

During gestation, the placenta selects arachidonic acid and docosahexaenoic acid (DHA) at the expense of linoleic acid, a -linolenic acid and eicosapentaenoic acid (EPA) resulting in substantially higher proportions of arachidonic acid and DHA in the fetal circulation at mid-term (Crawford et al., 1976) and term (Olegard and Svennerholm, 1970). This is denied to babies born prematurely. Low birth weight and prematurity are associated with a high risk of neurodevelopmental disorders and disabilities (Wynn and Wynn, 1981; Dunn, 1986; Hack et al., 1991; Scottish Low Birth Weight Study Group, 1992 a, b). The incidence of neurodevelopmental disorder among premature and low birth weight babies in the UK and Sweden is reported as having increased threefold since 1967 (Pharoah et al., 1990; Hagberg, Hagberg and Zetterstrom, 1989) adding urgency to the need for a better understanding of the nutritional needs of these infants.

Low birth weight. In a number of developing countries, low birth weight is a particular problem associated with a high incidence of perinatal and matemal mortality and morbidity. It is also a problem within urban areas of developed nations, especially among lower socio-economic groups. Worldwide, WHO estimates that 17.4 percent of babies are born at low birth weights. This has important long term implications for the children's health and abilities (FAO/WHO, 1992).

Teenage pregnancies pose a special problem since the nutritional intake of the mother needs to support her own continued somatic growth as well as that of the fetus. The vulnerability of teenage mothers and their offspring is borne out by the high frequency of perinatal mortality, low birth weight and maternal morbidity and mortality. However, when pregnant teenagers eat adequately throughout their pregnancies, delivery outcomes may be successful.

While a relationship exists between maternal nutrition and birth weights (Caan et al., 1978), the causes of low birth weight are multifactorial, including: low caloric intake, low weight gain during pregnancy, low prepregnancy weight, short stature and disease (for example, malaria) (FAO/WHO, 1992). In developed countries, smoking presents an additional factor. Several nutrients, independent of smoking, are related to birth weight up to 3.0kg (Doyle et al., 1990). Retrospective evidence suggests that fetal nutrition is a determinant of risk of non-insulin-dependent diabetes and vascular disease in later life (Barker et al., 1993). This concept is supported by evidence of deficits of arachidonic acid, DHA and vitamin A in the circulation of low-birth weight newborns (Ongari et al., 1984; Crawford et al., 1989, 1990; Carlson et al., 1992; Leaf et al., 1992) and by evidence of vascular pathology in the placenta of low birth weight babies (Althabe, Laberre and Telenta, 1985; Winick, 1983).

Micronutrients andfat store. In many developing countries, vitamin A deficiency is still prevalent. An adequate intake of fat and fat soluble vitamins under these circumstances is important and there should be an effort to raise the percentage of dietary energy from fat to at least 20 percent for women of reproductive age. This strategy should also help to ensure an adequate supply of essential fatty acids and fat soluble vitamins.

Body fat plays a special role insofar as women on low fat and low-calorie diets and highly trained athletes may not conceive, or the embryonic and fetal development of their offspring may be jeopardized (Frisch, 1977). The mother's fat store at the time of conception will be relevant to maternal hormonal responses and to the nourishment of the embryo. Similarly, it will provide the basis for subsequent fat storage and utilization during the pregnancy (FAO/WHO, 1978). To ensure adequate nutritional preparation, women should not be on slimming, low calorie or low fat diets in the three months prior to conception. Calorie and nutrient intakes should be adequate to meet the general recommendations for the first trimester of pregnancy whilst essential fatty acid intakes should be similar to those mentioned below for the pregnancy itself to ensure an adequate quality of the fat store. The need for adequate nutritional status in terms of calories, vitamins, minerals and trace elements before conception should receive attention.

Pregnancy. An additional requirement for dietary fat is present throughout the nine months of pregnancy to provide for the fat storage in the early trimester and the growth in other compartments during the later trimesters. In the first trimester, the development of the embryo imposes a negligible quantitative demand for additional essential fatty acids, however, normal maternal fat deposition and uterine growth as well as the preparative development of the mammary gland do make significant demands. In the second and particularly the third trimester, the expansion of blood volume, placental and fetal growth add to the demand. Based on accretion data for these compartments, an average total of 600 g of essential fatty acids (approximately 2.2 g/day) will be acquired throughout a normal pregnancy of a well-nourished woman. Increased energy utilization may modify this need. This is consistent with the recommendation on increased energy requirements (WHO, 1985a) and will maintain the linoleic to a -linolenic balance with a ratio of 1:5 to 1:10.

This recommendation presumes adequate conversion of both parent essential fatty acids to their long-chain polyunsaturated fatty acid derivatives. However, recent studies suggest that a relative deficiency of long-chain polyunsaturated n-3 fatty acids develops during pregnancy (Holman, Johnson and Ogburn, 1991). Correlations between arachidonic acid and birth weight and between DHA and gestational age (Leaf et al., 1992) are consistent for either indicator of maturation and with DHA intakes. There is evidence that high fish intakes are associated with longer gestation, higher birth weights and a reduced incidence of premature births. An intervention study with fish oils indicates that long-chain polyunsaturated n-3 fatty acids play a role (Olsen et al., 1992). If these data are confirmed, this could indicate the need to consider DHA preformed to help prevent premature birth and pregnancy-related hypertension (WHO, 1985a).

Lactation. During lactation, there are increased nutrient and energy requirements. The additional energy requirement for lactation, assuming there has been an appropriate energy store laid down during pregnancy, is 500 kcals/day (WHO, 1985a). If the stores are limited, the energy need can be as high as 800 kcals/day. Fat output is the most variable component of milk and this depends, qualitatively and quantitatively, on maternal nutrition and prolactin secretion. The diet of a wellnourished mother provides the unsaturated fatty acids within a range that assures the essential fatty acid supply to the infant. The overall energy may be supplied by any source but the essential fatty acid component is fully dependent on fat in the diet and maternal stores. If a woman was well-nourished throughout pregnancy, her fat stores can provide approximately one-third of the energy and essential fatty acids needed for the first 3 months of lactation. Based on the composition of milk from omnivorous women, the mother's diet during lactation should provide an additional 3 to 4 g/day of essential fatty acids in the first trimester of lactation which should rise to 5 g/day as the fat stores become depleted (Koletzko, Thiel and Abiodun, 1992) (Table 7.1). It should be possible to do this by increasing normal food intake.

Infant nutrition

The premature infant. During the last decade, evidence on the accretion of parent essential fatty acids and derived long-chain polyunsaturated fatty acids for fetal and neonatal growth has become available (Martinez, 1988). Modern analytical techniques have provided substantial data on the fatty acid composition of human milk (Ibid. ). Babies born prematurely are denied the intra-uterine supply of arachidonic acid and DHA. In addition, they are born with little or no fat reserves making them fully dependent on the diet. Despite the provision of ample linoleic acid and rising linoleic acid levels in the plasma, it is evident that arachidonic acid and other polyunsaturated fatty acids (of at least 20 carbon atoms in length) drop rapidly (Leaf et al., 1992). Present assessment of essential fatty acid status is dependent on the measurement of plasma and red cell composition. While there are limited data on tissue pools, the primate data suggest that they do correlate (Neuringer, Anderson and Connor, 1988). Retinal and visual cortical function show the effects of tissue essential fatty acid status.

TABLE 7. 1
Average fatty acid values of mature human milk in Europe and Africa

	Medians and Ranges
	Europe (14 studies)	Africa (10 studies)
Fatty acid totals (% wt/wt)
Saturated	45.2 (39.0-51.3)	53.5 (35.5-62.3)
Monounsaturated	38.8 (34.2-44.9	28.2 (22.8-49.0)
n-6 + n-3 PUFA	13.6 (8.5-19.6)	16.6 (6.3-24.7)
n-6 PUFA (% wt/wt)
C₁₈:2n-6	11.0 (6.9-16.4)	12.0 (5.7-17.2)
C₂₀:2n-6	0.3 (0.2-O.S)	0.3 (0.34.8)
C₂₀:3n-6	0.3 (0.2-0.7)	0.4 (0.2-0.5)
C₂₀:4n-6	0.5 (0.2-1.2)	0.6 (0.3-1.0)
C₂₂:4n-6	0.1 (0.1-0.2)	0.1 (0.0-0.1)
C₂₂:5n-6	0.1 (0.0-0.2)	0.1 (0.1-0.3)
Total n-6 LCP	1.2 (0.4-2.2)	1.5 (0.9-2.0)
n-3 PUFA (%wt/wt)
C₁₈:3n-3	0.9 (0.7-1.3)	0.8 (0.1-1.44)
C₂₀:5n-3	0.2 (0.0-0.6)	0.1 (0.1-0.5)
C₂₂:5n-3	0.2 (0.1-0.5)	0.2 (0.1-0.4)
C₂₂:6n-3	0.3 (0.14.6)	0.3 (0.1-0.9)
Total n-3 LCP	0.6 (0.3-1.8)	0.6 (0.3-2.9)

Source: Adapted from Koletzko, Thiel and Abiodun, 1992.

Several studies on biochemical indices of essential fatty acid status documented the effect of adding long-chain polyunsaturated fatty acids to the diet (Koletzko et al., 1989; Carlson et al., 1992; Uauy, Birch and Birch, 1992; Makrides et al., 1993). If both arachidonic acid and DHA are added, the post-natal drop in blood plasma level can be ameliorated. If marine oil supplementation is used (EPAIDHA = 2: 1) this compromises the level of arachidonic acid which was found to adversely affect growth in one study (Carlson et al., 1992). There is convincing evidence that supplementation with DHA from marine oil improves the development of the rod photoreceptor and visual acuity, a measure of the receptor response to light, as well as the cortical, which is associated with cognitive ability to integrate information (Uauy et al., 1990; Uauy, Birch and Birch, 1992; Birch et al. 1992; Carlson 1993a). The initial concern (Carlson et al., 1992) that poor growth, associated with marine oil, was linked to depressed arachidonic acid status has been removed by using a low EPA marine oil with an EPA/DHA ratio of 1:10. This did not compromise weight gain and resulted in higher Bayley mental development scores at 12 months (Carlson et al., 1993 b). Eight year follow-up studies which compared premature babies who were fed human milk by tube with those fed formula showed an IQ which was eight points lower in those children who had been fed formula (Lucas et al., 1992).

There are limited data on the accretion of essential fatty acids of normal fetuses and healthy infants fed human milk and no quantitative human data on the metabolic conversions. Although there are variations in maternal diets, milk composition data obtained from omnivorous women were the basis for the consultation's recommendation. As a guide, formula for preterm babies should provide a mean of 700 mg linoleic acid, 50 mg a -linolenic acid, 60 mg of arachidonic acid and its associated long chain n-6 fatty acids, and 40 mg of DHA per kg body weight. That is, 5.6 percent of the energy as parent essential fatty acids and 0.8 percent as long-chain polyunsaturated fatty acids. Because of the known interference of linoleic acid with the metabolism of the long-chain polyunsaturated fatty acids, linoleic acid should not exceed 10 percent of the total energy. Until more data are available, particularly dose response data, the other fatty acids as mentioned above should remain within approximately 30 percent of the target recommendation. The remaining fatty acids should be selected on the basis of digestibility, lack of interference with essential fatty acid metabolism and other measures of function. In principle, a mixture of oleic and saturated fatty acids with a predominance of oleic appears to meet these conditions.

Term infants. Whenever possible, the preferred source of infant nutrition is human milk. In view of the evidence, education and health care programmes should actively promote breast feeding. In addition, because of the long term nutritional interactions with the mother even prior to conception and their profound implications for public health, similar programmes should be developed for women prior to conception, through pregnancy and lactation. Such programmes will improve maternal health, fetal development and neonatal nutrition.

When term infants who died from unexplained causes were compared, those infants who were fed milk formula without arachidonic acid and DHA had reduced levels of brain cortical DHA and higher n-6 docosapentaenoic acid (an index of DHA deficiency) than those fed breast milk (Farquharson et al., 1992). As the data on preterm infants now demonstrate, there are advantages for both rod photoreceptor and neural function to supplementing with n-3 long-chain polyunsaturated fatty acids; it would seem proper to provide both arachidonic acid and DHA preformed in term infant formula milks in similar proportions to breast milk from well-nourished, omnivorous mothers. For term infants, the provision, per kilogramme of body weight should amount to 600 mg of linoleic acid, 50 mg of a-linolenic acid, 40 mg of arachidonic acid and its associated n-6 fatty acids and 20 mg of docosahexanoic acid. Although there is not yet evidence from controlled, randomized trials in term infants, this is suggested to provide for the greatest possible release of the full genetic potential for neural and visual development.

As it has evolved, human milk provides long-chain polyunsaturated fatty acids preformed. In view of the evidence on the higher efficiency of long-chain polyunsaturated fatty acids for neural development (Sinclair, 1975; FAO/WHO, 1978; Leyton, Drury, and Crawford, 1987) and the data on premature infants discussed above, the long-chain polyunsaturated fatty acids should be included in infant formula. Providing parent essential fatty acid at a ratio which is claimed to optimize conversion to long-chain polyunsaturated fatty acids should be proven valid for physical, vascular and mental development and should provide for biochemical and functional normalcy. The burden of proof should be placed on those proposing that artificial formula should, in principle, be dissimilar to breast milk (Drury and Crawford, 1990).

These recommendations for term and preterm infants are broadly in agreement with those of the British Nutrition Task Force on Unsaturated Fatty Acids (BNF, 1992).

Weaning. Human milk provides 50 - 60 percent of its energy as lipid in which about 5 percent of the energy is essential fatty acid with 1 percent as long-chain polyunsaturated fatty acids. Six-month follow-up studies of lactation in a randomised trial showed that in wellnourished mothers, milk fat contribution increased from 40 - 50 g/litre at three weeks to 60 - 70 g/litre at 4-6 months (WHO, 1985b; Sas et al., 1986). In developing countries with lower energy intakes, the rise in milk fat content was less. It would, therefore, seem especially inappropriate to wean babies on to low fat diets.

The European Society of Paediatric Gastroenterology and Nutrition (1991) recommended that 40-55 percent of the dietary energy be provided as fat (4.4-6.0 g/100 kcal) for follow-up formula. During weaning, the fat component should provide 30-40 percent of the dietary energy and similar levels of essential fatty acids as are found in breast milk from appropriate foods until at least two years of age.

In practice, this means that complementary food used during the weaning period should include adequate amounts of fats and oils as the breast milk component of the diet declines. Commonly, infants in many developing countries are weaned on to cereal or tuber-based diets with a low energy density. In these countries, there is a need to reinforce educational messages about the use of vegetable oils or oil containing foods in the diet of weanling infants and young children.

Sources

It is acknowledged that human milk is the best and only time-proven source for fat and long-chain polyunsaturated fatty acids in neonate diets. Sources of long-chain polyunsaturated fatty acids that have been tested include egg phosphoglycerides, fish oils and fish oil fractions. Novel sources of fat which have been developed include phosphoglycerides from animal tissues, algal and microbial lipids. The safety and efficacy of novel sources should be adequately tested before they are added to infant formula.

Cooking oils

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Cooking oils

The major use of cooking oil is in frying, where it functions as a heat transfer medium and contributes flavour and texture to foods. One requirement of a cooking oil is that it be stable under the very abusive conditions of deep-fat frying, namely, high temperatures and moisture. In general, oil should be kept at a maximum temperature of 180°C during frying. Frying food at a temperature which is too low results in increased fat uptake. Water, which is contributed by the foods that are fried in an oil enhances the breakdown of fatty acids which occurs during heating. Hydrolysis results in a poor-quality oil that has a reduced smokepoint, darkened colour and altered flavour. During heating, oils also polymerize, creating a viscous oil that is readily absorbed by foods and that produces a greasy product. The more saturated (solid) the oil, the more stable it is to oxidative and hydrolytic breakdown, and the less likely it is to polymerize.

Oils rich in linolenic acid, such as soybean and canola oils, are particularly susceptible to these undesirable changes. When soybean oil is partially hydrogenated to reduce the linolenic acid from about 8 percent to below 3 percent, it is a relatively stable frying oil and it is used in processed fried foods, pan and griddle frying, and sauces. Stability is increased by using cottonseed, corn oil, palm oil or palmolein or by more hydrogenation of soybean oil.

Foods that are fried and stored before eating, for example, snack products, require an even more stable oil. More saturated oils improve stability, however, if the frying fat is solid at room temperature it will produce a dry dull surface that is undesirable on some fried products. When oils are used continuously, as in restaurants, a frying fat which can withstand very heavy use is needed. In these cases, more solid shortenings are used to maximize the stability of the fat for many hours of frying.

Frying oils made from sunflower and safflower have lower stability because of their high polyunsaturated fatty acids and low g -tocopherol content; however, high-oleic safflower and sunflower oils that have been genetically developed are suitable frying oils.

For optimal use of cooking oils, it is necessary to distinguish between different frying conditions. The most important parameters to be monitored are duration of use and nature of the foods to be fried. If food fats enter the frying oil, food components could destabilize the oil and the water content of the material could influence the frying operation. Whether the use is continuous or intermittent is relevant, continuous use provides a protective water vapour blanket that protects against oxidation. Finally, temperature must be considered.

Industrial use of fats and oils is usually well-monitored. The continuous operation (implying the constant addition of fresh oil) and quality requirements for the products normally ensure good quality control of the oil. In homes, where oils are normally used for much shorter periods of time and are discarded after being used once or twice, stability problems play a lesser role. Stability of frying oils is a more important factor in catering operations, where heating is intermittent and oils may be used for long periods.

Margarines

Margarines must have some crystalline structure to maintain a semisolid consistency at refrigerator and room temperatures. Sharp melting at body temperature is needed so that the margarine will melt rapidly in the mouth leaving no waxy feeling.

Oleic acid melts at 16°C, whereas elaidic acid melts at 44°C, so that the presence of some trans isomers may vastly raise the melting point and stability of a product. Stick-type margarines contain 1029 percent trans fatty acids while tub-type margarines have 10-21 percent trans fatty acids. In addition to partial hydrogenation, the correct consistency of a margarine can be obtained by blending soft and hard fats. Lower fat spreads, for example, 40 percent or 60 percent fat, contain less trans fatty acids.

Another important feature in solidifying oil for margarines is the type of crystal formed. Fats are polymorphic, that is, they are capable of forming several different types of crystals. The a crystals are the tiniest, forming a smooth but unstable crystal. The b ' crystals are medium in size, still they are generally desirable in margarines because they impart a smooth texture, are fairly stable, and ensure plasticity of the product. The largest crystals are the b type which are stable and grainy, and generally undesirable. Also, the , b form is readily converted to a hard and brittle structure. Products such as liquid shortenings and coating fats sometimes require the ,bcrystal.

The lengths of fatty acids and their positions on the glycerol backbone determine the type of crystal formed. The triacylglycerols in a certain fat or solidified oil always form the same type of crystals unless other ingredients are added to alter crystal formation. To produce a margarine with enhanced , b ' stability, it is necessary to have a variety of triacylglycerols with different fatty acid chain lengths. Palm and hydrogenated cottonseed oils contain a fair amount of C16:0 and can be added to other oils to enhance b ' structure.

Shortenings

Shortenings are semisolid fats that impart a "short" or tender quality to baked goods, enhance the aeration of leavened products, and promote a desirable grain and flavour. They coat the gluten proteins of flour which prevents toughness. In contrast, toughness is desirable in yeast-raised products to give a chewy texture. For products with characteristics between breads and cakes such as doughnuts, shortening modifies the gluten and adds richness to the product. In baked goods, shortenings are used specifically to leaven, cream and lubricate. In icings and fillings, the fats help to form tiny air bubbles that create a light and fluffy structure. Shortenings used as stable frying fats provide a heating medium, and their crystalline structures are not important.

The requirements of fats with properties for shortening are fairly specific depending upon the food in which they are used. Bakery shortenings should have as wide a plastic range as possible, that is, the melting behaviour should remain constant over a specified temperature range, often 24-42°C. This quality allows the fat to be easily manipulated without melting at room temperature and enhances its mixing ability. A wide plastic range is accomplished by blending a partially hydrogenated stock with a fully hydrogenated oil such as soybean (,b crystal) or cottonseed and palm (b ' crystal). The b ' crystal is often preferred because it results in a creamier texture.

Salad oils

A major use of salad oils is in pourable salad dressings. Traditional salad dressings, some of which are emulsified, consist of a two-phase system of oil and water with 55-65 percent oil. A salad oil coats the salad ingredients, spreading the flavour of the dressing that improves the palatability of the salad. The other major use of salad oils is in mayonnaise and thick salad dressings, which contain 80 and 35-50 percent oil, respectively. The oil in mayonnaise is responsible for viscosity, whereas the oils in thick salad dressings help to modify the mouthfeel of the starch paste that thickens the product.

A salad oil must not contain solid crystals that, when refrigerated, would impart a waxy, tallowy texture, would break the emulsion formed between water and oil, or would give the product a cloudy appearance. Oils can be winterized, a process that removes solid crystals formed at refrigerator temperatures.

Typically, unhydrogenated or partially hydrogenated soybean, canola, winterized cottonseed, safflower, sunflower, and corn oils are used. Olive oil has a unique flavour, although it forms crystals at refrigerator temperature, it is often served at room temperature as a salad oil.

Medium-chain triglycerides (MCT)

In addition to the common dietary fats, lipid fractions such as medium-chain triglycerides (MCT oil) are used in specialized therapeutic preparations. MCT oil is a fraction of coconut oil containing fatty acids of 8-10 carbon atoms in triacylglycerols. MCT oil is used in formulas for enteral feeding and in diets for patients with malabsorption syndromes.

Conclusion

The range of food uses requires a variety of fats and oils with characteristics tailored to meet these needs. Efforts to modify the composition of fats and oils may be limited by these various technical requirements.

Rural vegetable oil production

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Rural vegetable oil production

Rural oil extraction usually occurs near the areas of raw material production. This provides the smallscale processor with access to raw materials, helps to ensure that perishable oil crops are processed quickly, and reduces transport costs. For rural communities and the urban poor, unrefined vegetable oils contribute significantly to the total amount of oil consumed. Crude oils are affordable to low-income groups and serve as important sources of b -carotene and tocopherols.

To maintain the quality of the raw material, care is needed during and after the harvesting of oilbearing fruits that are perishable and susceptible to fat breakdown. Bruising of fresh palm fruits accelerates lipase activity leading to fat degradation. Oil-bearing crops such as sheanuts are prone to mould infestation during storage. This is curtailed by heat treatment: steaming or boiling, coupled with sun-drying to reduce the moisture content.

Storage. The moisture content of oil seeds and nuts influences the quality of raw materials over time. In most rural operations, sun-drying reduces the moisture content of oil seeds to below 10 percent. Adequate ventilation or aeration of the seeds or nuts during storage ensures that low moisture levels are maintained and microbial development is avoided. This is important in the storage of groundnuts which are highly susceptible to aflatoxin contamination through the growth of Aspergillusflavus. Since aflatoxins and pesticides are not removed by rural extraction techniques, microbial contamination and the application of insecticides should be avoided. There is a need for storage practices which are affordable and available to the small-scale processor. Perishable raw materials such as palm fruits should be processed as soon as possible after harvesting.

In humid developing countries, the sun-drying of oil seeds with a high moisture content, such as mature coconut, is slow and inefficient. Such conditions promote mould growth which results in high free fatty acid levels and poor organoleptic qualities. Coconut oil for human consumption should be obtained soon after harvest.

Pre-treatment. The first operation after harvesting involves sterilization and heat treatment by steaming or boiling, this inactivates lipolytic enzymes which could cause rapid degradation of the oil and facilitates the pulping of the mesocarp for oil extraction. "Sterilised" palm fruits are pulped in a wooden pestle and mortar or mechanised digestor.

Decortication or shelling separates the oil-bearing portion of the raw material and eliminates the parts that have little or no nutritional value. Small-scale mechanical shellers are available for kernels and nuts although manual cracking is still prevalent.

Most oil seeds and nuts are heat-treated by roasting to liquify the oil in the plant cells and facilitate its release during extraction. All oil seeds and nuts undergo this treatment except palm fruits for which "sterilization" replaces this operation.

To increase the surface area and maximize oil yield, the oil-bearing part of groundnuts, sunflower, sesame, coconut, palm kernel and sheanuts is reduced in size. Mechanical discattrition mills are commonly used in rural operations.

Extraction. In oil extraction, milled seed is mixed with hot water and boiled to allow the oil to float and be skimmed off. The milled oil seed is mixed with hot water to make a paste for kneading by hand or machine until the oil separates as an emulsion. In groundnut oil extraction, salt is usually added to coagulate the protein and enhance oil separation.

A large rotating pestle in a fixed mortar system can be powered by motor, humans or animals to apply friction and pressure to the oil seeds to release oil at the base of the mortar. Other traditional systems used in rural oil extraction include the use of heavy stones, wedges, levers and twisted ropes. For pressing, a plate or piston is manually forced into a perforated cylinder containing the milled or pulped oil mass by means of a worm. The oil is collected below the perforated chamber. A variety of mechanical expellers have been designed. The pre-heated raw material is fed into a horizontal cylinder by a wormshaft. By means of an adjustable choke, internal pressure which is built up in the cylinder ruptures the oil cells to release the oil.

Dehydration. By boiling in shallow pans, traces of water in crude oil are removed after settling. This is common in all rural techniques which recognize the catalytic role of water in the development of rancidity and poor organoleptic qualities.

Pressed cakes. A by-product of processing, the pressed cake, may be useful depending on the oil extraction technique applied. Cakes from water-extracted oil are usually depleted of nutrients. Other traditional techniques, for instance, those used for groundnut and copra ensure that the by-products, if handled with care, are suitable for human consumption.

Traditional technologies. In many countries, traditional processes for producing oil are very important, especially among communities which have easy access to raw oleaginous materials. Traditional processing tends to be environmentally sound and the skills required are family or group activities, involving women in particular. In a changing industrial atmosphere, these positive features have been outweighed by the negative aspects of traditional processing such as small production capacities, poor economies of scale, high expenditures of energy and time, and the cost of transporting oils to markets.

Large-scale production

Storage. Many steps in industrial processing find their origin in the traditional processes. In large-scale operations, oilseeds are dried to less than 10 percent moisture. They may be stored for prolonged time periods under suitable conditions of aeration with precautions against insect and rodent infestation. Such storage reduces mould infection and mycotoxin contamination and minimizes biological degradative processes which lead to the development of free fatty acids and colour in the oil.

Oil-bearing fruits such as olive and palm are treated as quickly as possible. Palm is sterilized as a first step in processing. Adipose tissues and fish-based raw materials (that is, the body or liver) are rendered within a few hours by boiling to destroy enzymes and prevent oil deterioration.

Processing. Oilseeds are generally cleaned of foreign matter before dehulling. The kernels are ground to reduce size and cooked with steam, and the oil is extracted in a screw or hydraulic press. The pressed cake is flaked for later extraction of residual fat with solvents such as "food grade" hexane. Oil can be directly extracted with solvent from products which are low in oil content, that is, soybean, ricebran and corn germ.

After sterilization, oil-bearing fruits are pulped (digested) before mechanical pressing often in a screw press. Palm kernels are removed from pressed cakes and further processed for oil. Animal tissues are reduced in size before rendering by wet or dry processes. After autoclaving, tissues of fish are pressed and the oil/water suspension is passed through centrifuges to separate the oil.

Oil Refining. Refining produces an edible oil with characteristics that consumers desire such as bland flavour and odour, clear appearance, light colour, stability to oxidation and suitability for frying. Two main refining routes are alkaline refining and physical refining (steam stripping, distillative neutralisation) which are used for removing the free fatty acids.

The classical alkaline refining method usually comprises the following steps:

Step 1. Degumming with water to remove the easily hydratable phospholipids and metals.

Step 2. Addition of a small amount of phosphoric or citric acid to convert the remaining non-hydralable phospholipids (Ca, Mg salts) into hydratable phospholipids.

Step 3. Neutralising of the free fatty acids with a slight excess of sodium hydroxide solution, followed by the washing out of soaps and hydrated phospholipids.

Step 4. Bleaching with natural or acid-activated clay minerals to adsorb colouring components and to decompose hydroperoxides.

Step 5. Deodorising to remove volatile components, mainly aldehydes and ketones, with low threshold values for detection by taste or smell. Deodorisation is essentially a steam distillation process carried out at low pressures (2-6 mbar) and elevated temperatures (180-220°C).

For some oils, such as sunflower oil or rice bran oil, a clear table product is obtained by a dewaxing step or crystallization of the wax esters at low temperature, followed by filtration or centrifugation.

The alkaline neutralisation process has major drawbacks, the yield is relatively low and oil losses occur due to emulsification and saponification of neutral oil. Also, a considerable amount of liquid emuent is generated. The soaps are generally split with sulphuric acid to recover free fatty acids along with sodium sulphate and some fat-containing acid water steam.

In physical refining, the fatty acids are removed by a steam distillation (stripping) process similar to deodorisation. The low volatility of fatty acids (depending upon chain length) requires higher temperatures in physical refining than those required for only deodorisation. In practice, a maximum temperature of 240-250°C is sufficient to reduce the free fatty acid content to levels of about 0.05-0.1 percent. A prerequisite for physical refining is that phosphatides be removed to a level below 5 mg phosphorus/kg oil. In the classic refining process, this level is easily achieved during the neutralisation stage, but special degumming processes may be required for physical refining of high-phosphatide seed oils. These procedures rely on improved hydration of phospholipids by intimate contact of the oil with an aqueous solution of citric acid, phosphoric acid andlor sodium hydroxide, followed by bleaching (Segers and van de Sande, 1988).

It is unlikely that the mild reaction conditions during degumming and neutralisation will induce any significant undesirable changes in the oil composition. On the contrary, several impurities including oxidised components, trace metals and colouring materials are partially removed by entrainment with the phospholipids and soapstock. These impurities are further reduced during bleaching. Neutralisation also contributes significantly to the removal of contaminants such as aflatoxin and organophosphorous pesticides (Thomas, 1982). Organochlorine pesticides and polycyclic aromatic hydrocarbons, if present, must be removed during the deodorisation/stripping stage and by active carbon treatment. Some loss of tocopherols and sterols during alkaline neutralisation usually occurs, however, under wellcontrolled conditions (minimising air contact) this need not exceed 5-10 percent (Gertz, 1988; Johansson and Hoffmann, 1979).

Potential side reactions during high-temperature processing

The possibility of negative effects of high temperatures during deodorisation and stripping has evoked concern. In several studies, extreme conditions of temperature and time (even with free access of air) were applied to produce significant quantitative results. However, the results of model studies should be related to practical processing conditions. As early as 1967-1979, the German Society for Fat Research (DGF) defined upper limits for deodorisation conditions [240°C for 2hrs, 270°C for 30 min.] (Fremdstoff-Kommission, 1973; Gemeinschaftsarbeiten, 1992).

Good manufacturing practice also implies the following: the use of stainless steel equipment; the careful deaeration at < 100°C before heating to the final stripping temperature; the use of oxygen-free steam; and strict feedstock specifications (typically: Fe 0.1, Cu 0.01, P S, bleaching earth 5 mg/kg oil max.).

Investigations in which oil was maltreated under extreme conditions (Rossel, Kochhar and Jawad, 1981; Jawad, Kochhar and Hudson, 1983 a, b; 1984) determined the effects of temperature (240-300°C) and time (30-180 min.) during "physical refining" of soybean oil (degummed with phosphoric acid and lightly bleached, but still containing 20 mg P, 0.35 mg Fe and 0.05 mg Cu per kg oil). A strong effect of temperature on the formation of trans fatty acids and polymeric compounds is shown in Figure 5.1. Time also has a significant effect. At 280-300°C, there was evidence for appreciable inter- or intra-esterification (increase in the content of saturated fatty acids at the 2-position of the triacylglycerols); substantial amounts of conjugated fatty acids were formed as well. The shaded areas indicate the usual range of processing conditions required for physical refining (270°C for 30 mini 250°C for 1 h; 240°C for 2 h; 220°C for 3 h). Under these conditions, all changes induced by the high temperature treatment appear to be relatively minor.

FIGURE 5.1 : Formation of various artefacts in soybean oil under extreme conditions of heat treatment

Cis-trans isomerisation. One of the most sensitive parameters used to detect chemical changes resulting from severe processing conditions is cis-trans isomerisation, especially of linolenic acid. The most complete study in this area was made by Eder (1982), who investigated the formation of geometric isomers in various oils on the laboratory, pilot plant and production scales. On a laboratory scale, with unbleached soyabean oil at 240ºC, the formation of C₁₈:3 isomers (determined by GLC) was insignificant (less than 1 percent, even after 5 h, against 3 percent at 260°C). The total trans contents (determined by infrared spectroscopy) for several types of oils deodorised in stainless steel equipment on the pilot plant scale is depicted in Figure 5.2. The data show a strong effect of temperature, especially between 240 and 270°C, and confirm the general trend. That is, even for highly unsaturated oils containing linolenic acid, the formation of trans isomers is slow under the conditions recommended for industrial deodorisation/physical refining (for example, 250°C max.). In conclusion, in the temperature range of 240-250°C, the amount of trans fatty acids formed from unsaturated oils is about 1 percent or less per hour. This figure is consistent with the data discussed earlier (Rossell, Kochhar and Jawad, 1981; Jawad, Kochhar and Hudson, 1983b). Heating of oils in air, under simulated frying conditions, has led to similar types of isomerised fatty acids (Grandgirard, Sebedio and Fleury, 1984; Grandgirard and Juillard, 1987; Sebedio, Grandgirard and Provost, 1988).

FIGURE 5.2 : Trans fatty acid formation during high temperature deodorisation of various oils

The formation of positional isomers (that is, double bonds shifted along the fatty acid chain) of linolenic and linoleic acid under deodorisation/physical refining conditions has not been reported.

Dimensahon and polymensahon. Quantitative data on the formation of polymeric compounds from bleached soybean oil are included in Figure 5.1 (Jawed, Kochhar and Hudson, 1983b). Up to about 260°C, their rate of formation appears to be low; above 260°C, the increase is more rapid. Similar trends were observed by Eder (1982). A rapid increase of the amount of polymeric triacylglycerols was only observed at 270°C. Deodorisation of soybean oil on a commercial scale (2 x 51 min at 240°C) resulted in an increase of 0.5 percent to 0.8 percent polymeric triacylglycerols.

When the temperature was increased to 270°C in one of the deodoriser trays, 1.5 percent polymers was found. This suggests that the content of di- and polymeric triacylglycerols do not normally exceed l percent by weight in properly refined oils and fats.

Strauss, Piater and Sterner (1982) carried out toxicological studies on mice fed concentrates (24 or 96 percent) of dimeric (incl. polymeric) triacylglycerols isolated from soybean oil that had been deodorised for 3.5 h at 220°C and 1 h at 270°C and contained 1.5 wt percent of dimers. The acute toxicity was found to be low with an LD 50 above 18 g/kg body weight. Long term administration of the dimer concentrate (12 months, 15 wt percent of the 24 percent concentrate in the diet) did not reveal any significant differences compared with the control group. The absorption of dimeric fatty acids was found to be poor. Therefore, the presence of small amounts of dimers and polymers in processed oils does not seem to present a physiological problem.

Physical losses

During deodorisation or physical refining, volatile components are removed from the oil by the combination of high temperature, low pressure and stripping action of inert gas (steam). The degree of removal depends on the physical properties of the components (especially vapour pressure) and on the temperature and volume of steam passed through the oil. Some physical losses are highly desirable, for example, the removal of off- flavours, pesticides and polycyclic aromatic hydrocarbons, if present. Other losses of nutritionally valuable components, such as tocopherols and sterols, are potentially undesirable.

Quantitative data on the composition of deodoriser distillates and the removal of various types of contaminants from oils during deodorisation were reported (Chaudry, Nelson and Perkins, 1978; Larsson, Eriksson and Cervenka, 1987; Sagredos, Sintra-Roy and Thomas, 1988; Gemeinschaftarbeiten, 1990). During high temperature deodorisation or physical refining, especially, the concentrations of organochlorine pesticides (lindane, DDT etc.), if present in the bleaching oil, are reduced to very low levels.

Polycyclic aromatic hydrocarbons (PAM) have been a reason for concern since they were detected in some types of crude oils and fats in the 1960s. An example of this is coconut oil from copra dried with non-purified smoke gases. Depending upon the number of aromatic rings, polycyclic aromatic hydrocarbons are classified as either light (3-4 rings) or heavy (5 or more rings). Some of these compounds have proven carcinogenic properties, for example, benz-a -pyrene. Light polycyclic aromatic hydrocarbons can be removed by deodorisation or physical refining, whereas heavy polycyclic aromatic hydrocarbons can be removed only by adsorption onto activated carbon (Chaudry, Nelson and Perkins, 1978; Larsson, Eriksson and Cervenka, 1987). This treatment, which can be combined with the bleaching process, is effective in reducing the amount of polycyclic aromatic hydrocarbons to acceptable levels.

Some loss of tocopherols and sterols by evaporation during high temperature deodorisation and physical refining is inevitable. However, they have higher molecular masses and lower volatilities than free fatty acids and light polycyclic aromatic hydrocarbons. Consequently, the losses of tocopherols and sterols need not be severe if the processing conditions are well-chosen. Extreme conditions applied in some model studies do induce more drastic effects. Typical results obtained for soybean oil (Rossell, Kochhar and Jawad, 1981; Jawad, Kochhar and Hudson, 1984) are illustrated in Figure 5.3. After 2 hrs at 300°C (a drastic treatment), the tocopherols and sterols almost completely disappeared, whereas the actual reduction during physical refining at 240°C for 120 min is only about 15-20 percent. The total refining losses (including pretreatment) are about 25-35 percent. Many investigators report similar data for a variety of oils. The losses tend to be higher in physical refining than in alkaline refining because of higher stripping temperatures.

Under extreme conditions, some isomerisation of b -sitosterol can occur and individual tocopherols (a ,b , t , d ) and sterols may behave differently when exposed to high temperatures (Jawed, Kochhar and Hudson, 1984). However, these phenomena are of minor significance under more realistic conditions. The percentage composition of the tocopherol and sterol fractions remains essentially unchanged during processing (Gemeinschaftarbeiten, 1990; Jung, Mood and Min, 1989).

For refined oils such as sunflowerseed, cottonseed and rapeseed oil, an upper limit of 3035 percent loss of tocopherols throughout the entire processing would still satisfy the generally accepted criterion of oc-tocopherol equivalents/linoleic acid ³ 0.6 mg/g (eager, 1975). Soybean oil, which is high in g -tocopherol and consequently well-protected in vitro, is relatively low in a -tocopherol and cannot reach this ratio.

The, b -carotene in palm oil is another valuable component that needs consideration in the refining process. Special processes for retention are being designed. Olive oil and sesame oil are used in unrefined form since a specific taste is expected by consumers.

FIGURE 5.3 : Reduction of tocopherol (A) and sterol (B) content of soybean oil during bleaching and severe heat treatment (time = 2 hours)

Fat modification processes

Hydrogenation. Hydrogenation of edible oils and fats has been applied on a large scale since the beginning of this century. The process is carried out in a three-phase system (hydrogen gas, liquid oil and solid catalyst) at temperatures ranging from about 120°C to about 220ºC max. in the final stages of the reaction. The catalyst consists of small nickel crystallites supported by an inorganic oxide, usually silica or alumina. After the reaction, the catalyst is filtered off and any traces of residual nickel are removed in post-refining to a level of about 0.1 mg/kg or below.

Hydrogenation is a series of consecutive reactions following pseudo first order reaction kinetics:

K₃	K₂	K₁
18:3----->	18:2------>	18:1------>	18:0

in which K₃, K₂ and K₁ are the reaction rate constants for linolenic, linoleic and oleic acid, respectively. The K3 is much larger than K2 and K,. In nearly all hydrogenations, linolenic acid is transformed into compounds which are less saturated. Depending upon the reaction conditions, the socalled Selectivity Ratio (K₂/K₁) can change significantly; for example, for nickel catalysts it varies from approximately 10 at a low temperature to 50 or 100 at high temperature. A high Selectivity Ratio implies that relatively little saturated acid is formed and that monounsaturated fatty acids are the dominant reaction product.

Apart from reduction of unsaturation, isomerisation of double bonds also takes place during hydrogenation: geometric isomerisation (cis-trans) and positional isomerisation. The mechanisms of hydrogenation and isomerisation are strongly interrelated (Koritala and Dutton, 1973; Rozendaal, 1976). Initially, a half-hydrogenated intermediate is formed in which the molecule adsorbed to the catalyst surface by a single bond can freely rotate. Addition of a second hydrogen atom results in saturation, whereas abstraction of a hydrogen atom from the half-hydrogenated intermediate to the nickel surface yields either the original molecule or a positional or geometric isomer. Hydrogenation of polyenoic fatty acids occurs, at least partially, through conjugated isomers (for example, c9, t11 or t10, c12) which are highly reactive and, therefore, rapidly converted into cis or trans monoenoic acids without accumulating. Of the total amount of trans fatty acids present in hydrogenated oils and fats, the greater part by far are trans monoenes. Due to the important role hydrogenation plays in the production of plastic fats, trans fatty acids may be found in considerable amounts in many products. The amount of cis,trans and trans,cis dienes is much smaller, whilst the level of trans,trans dienes seldom exceeds 1 percent. (Gottenbos, 1983).

Apart from hydrogenation, there are two other important fat modification technologies. The first is interesterification, the random rearrangement of the fatty acids in the triglyceride molecule under the influence of a moderately alkaline catalyst. This modifies the melting behaviour of the fat without changing the nature of the fatty acids. The second is fractionation, the controlled separation of oil/fat fractions by low temperature (dry fractionation), or solvents (solvent fractionation). In this process, there are no changes in the chemical nature of the fatty acids. Palm oil is fractionated into palmolein and palmstearin.

Interrelationships of fat modification technologies. Industry uses various oils and fats interchangeably while retaining constant quality. Generally, the least expensive combination of raw materials compatible with the required quality is chosen. Hydrogenation greatly extends the number of fats available with specified melting behaviour and this increases interchangeability and lowers costs. In non-hydrogenation situations, a combination of interesterification, fractionation and selection of the starting oil may be acceptable solutions for limiting the formation of isomers in terms of product quality, however, the costs are higher. While the actual specific modification, for example, hydrogenation or interesterification, is relatively inexpensive, the costs of losing flexibility can be significantly higher. The processes for oil modification may change as new compositions become available through plant biotechnology (Sommerville, 1993).

Other considerations

Storage, transport and packaging of oils. Oils and fats must be protected against oxidative deterioration, contamination with water, dirt, or other fats, absorption of foreign odours and tastes, thermal deterioration, and entry of foreign substances from packaging and lining materials. Temperature, oxygen pressure, oxidation products, trace metals, oxidative and lipolytic enzymes, reduction in natural antioxidants and visible and ultraviolet light are all factors in such deterioration. The use of low storage temperatures, nitrogen or vacuum packaging; the avoidance of copper, copper alloys and iron as construction material of storage vessels; and the use of synthetic or natural antioxidants and metal sequestrants as additives, work to prevent deterioration of oil during storage.

Selection of oil processing technology. The use of oil processing technology and its application in products is influenced by several factors. For example, the demand for triacylglycerols with specific fatty acids in the 1, 2 and 3 positions of the molecule can be met through enzymatic interesterification which uses lipases as catalysts in the interesterification process. The more readily absorbed fatty acid in the 2-position can provide for specific triacylglycerols with medical benefits. For example, essential fatty acids can be supplied to patients with various types of fat malabsorption or energy can be given to infants with palmitic acid in the 2-position. Another is the increased use of physical refining because of consumer pressure for less "chemical" processing.

Conclusions

Rural refining of oil-bearing plants can produce fats and oils of good quality which provide needed energy and fat soluble vitamins. Commercial refining produces fats and oils that can be of high quality and have the characteristics of bland taste, clear colour, good keeping quality and frying stability. Commercially-refined fats and oils are free from known contaminants extracted from the raw agricultural products. Refining may remove nutritionally valuable carotenoids to yield oils of low colour, but retains substantial proportions of tocols, and does not change fatty acid nor triacylglycerol compositions. Temperature, time and pressure must be carefully controlled during industrial refining. Oil products should be properly stored, transported and packaged to maintain quality and consumers must assume responsibility for not abusing oils and fats within households.

Industry can design almost any fat or oil for a specific application by the use of various modification processes, such as hydrogenation, interesterification, fractionation or blending. Hydrogenation typically reduces essential fatty acid content and creates various fatty acid isomers, both cis and trans. The wide flexibility available to industry through the selection of raw materials and different modification processes allows for the production of oils at the lowest cost possible, an important aspect of food production.

EDIBLE OIL REFINING

2012-07-21T01:55:00.000-07:00

PROCESS DESCRIPTION
EDIBLE OIL REFINING

The process of EDIBLE OIL REFINING in general comprises of Degumming, Neutralization, Bleaching and Deodorization and Winterisation. Chemical refining is the traditional method whereby the free fatty acid of the crude oils are neutralized with Caustic Soda. The resultant Sodium Soaps are removed by Batch Settling or by means of Centrifugal Separators. The neutral oils are subsequently bleached and deodorized. This method can be used for reliably refining virtually all crude oils, including oils of low quality, with the exception of Castor Oil.

In all alternative method of edible oil refining of Physical refining, the free fatty acids are removed by distillation in one stage of deodorizing. A fundamental criterion for using this method is that the crude oils should be degummed as effectively as possible, however this is only possible to a limited extent with some crude oil qualities. Other oils for instance cottonseed oil or fish oils, are fundamentally not suitable for Physical Refining.

BLEACHING

For Edible Oil Refining -

The unique CHEMPRO SOFT- BLEACH Bleaching system gently removes residual Phosphatides , metals , soaps and oxidation products in addition to colouring matter.

The washed and Neutralized oil is preheated and fed to the Bleacher through the Cascade Vacuum Dryer. Bleaching earth and activated carbon is added to the oil through the dosing unit which is controlled by a programmable controller. The Bleacher Proprietary designed with internal partitions and set of high efficiency turbine agitators to avoid short cycling and provide necessary retention time before filtration. The conjunction of vacuum dryer with a bleacher is what is unique about SOFT BLEACH where by oil going to the bleacher is thoroughly dried and deaerated in the cascade vacuum dryer and also the fugitive particles from the bleacher sucked under vacuum are scrubbed by the down coming oil.

The bleached oil from the Pressure Leaf Filters transferred to the bleached oil tank for intermediate storage. For Edible Oil Refining CHEMPRO has a unique advantage of deep knowledge of the sorption processes and understanding of surface phenomenon of various grades of Fullers Earths derived from attapulgite, sulfuric and hydrochloric Activated Earths derived from montmorillonite, Steam Activated Carbons and Chemically Activated Carbons. This makes them understand the bleaching process not superficially for removal of colour but also as a tool to remove undesirable toxic residues like pesticides, heavy metal, mineral oil traces.

DEGUMMING & NEUTRALIZATION

The Edible Oil Refining process depending on types of Phosphatides either water degumming, Acid Degumming, or Superdegumming is carried out so as to yield Phosphorous contents of less than 10ppm.

In Neutralization the predegummed oils or oils with very low phosphatide contents are saponified with Caustic Soda and the Sodium Soap is separated. The oil is initially heated to the optimum process temperature. In order to condition the non-hydratable phosphatides, a small quantity of concentrated phosphoric acid is added and intensively mixed with oil.

Following a brief reaction time, diluted caustic soda is added in order to neutralize the free fatty acid and the phosphoric acid. After mixing with the oil, the mixture is either conveyed directly to the first separator or it passes through a further reaction tank. The latter is recommended only for oils with a relatively high phosphatide content in the neutral oil is still too high for the subsequent process stages, and it must therefore be reduced further by one or two washings. For this purpose hot water is added to the oil, intensively mixed and the soapy wash water is removed in a further separator.

In general one wash stage is adequate. A second washing is only necessary if very low residual soap contents are required. Recently to reduce the water consumption in Edible Oil refineries we have pioneered the use of Silica Adsorbents for removal of residual soaps after neutralization. Upto 1000 ppm soaps are removed by sequential addition of silica adsorbent under presence of moisture at 65 C. The dosage of the silica adsorbents may vary from 0.1 to 0.2%.The silica adsorbents further also pick up polar impurities in oil and also gums to give a better edible oil in subsequent processes.

Refining of Edible oils

Babitha iyer

Taarak Mehta Ka Ooltah Chashmah

Contents

[edit]Plot

[edit]Gada Family

[edit]Mehta Family

[edit]Bhide Family

[edit]Iyer Family

[edit]Sodhi Family

[edit]Hathi Family

[edit]Other members

[edit]Cast and Characters

DILIP JOSHI (JETHALAL CHAMPAKLAL GADA

Contents

[edit]Career

[edit]Filmography

[edit]Television

[edit]Films

[edit]Awards

[edit]Indian Telly Awards

[edit]Zee Gold Awards

[edit]Lions Gold Awards

[edit]The Global Indian Film and Television Honours

[edit]BIG Star Entertainment Awards

Twenty for Twenty: Vegetarian Edition

The Ingredients

The Recipes

Hearty Vegetable Lasagna

Ingredients

Directions

Nutritional Information

What is Oil Refinery and Edible Oil Refinery?

Vegetarian Korma

Ingredients

Directions

Nutritional Information

List of vegetable oils

Major oils

[edit]Nut oils

[edit]Citrus oils

[edit]Oils from melon and gourd seeds

[edit]Food supplements

[edit]Other edible oils

[edit]Oils used for biofuel

[edit]Multipurpose oils also used as biofuel

[edit]Inedible oils used only or primarily as biofuel

[edit]Drying oils

[edit]Other oils

Weatherford Oil Tool M.E. Ltd, Kakinada

Gujarat State Petroleum Corporation Ltd., Kakinada

Acalmar Oils & Fats Limited, Kakinada

Oil Refining

Oil Refining

The Cream Always Rises

The Cream Always Rises

Separations

Separations

Description

Introduction

Separations

Extractions & Water washes

Multi stage, gravity fed, continuous counter current Extractions

FABs

Introduction

Centrifugal seperator

Sunflower oil

Contents

[edit]Composition

[edit]Physical properties

[edit]Uses

[edit]Nutrition

[edit]Health benefits

[edit]Diet and cardiovascular benefits

[edit]Restaurant and food industry uses

[edit]Skin protectant

[edit]Negative health effects

[edit]Preparation and storage

[edit]Methods of extraction

[edit]Refined versus unrefined

PROCESS DESCRIPTION
EDIBLE OIL REFINING