Vegetable fats and oils
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{{Vegetable oils}}
'''Vegetable fats and oils''' are substances derived from plants that are composed of [[triglycerides]]. Nominally, oils are liquid at [[room temperature]], and fats are solid; a dense brittle fat is called a [[wax]]. Although many different parts of plants may yield oil, <ref>Compare, for example, the [[Essential oil#Raw Materials|list of raw materials]] from which [[essential oil]]s are extracted.</ref> in actual commercial practice oil is extracted primarily from the [[seed]]s of oilseed plants.
The temperature-based distinction between oils and fats is imprecise, since definitions of room temperature vary, and typically any one substance has a ''melting range'' instead of a single ''[[melting point]]''.
[[Triglyceride]] vegetable fats and oils include not only edible, but also inedible vegetable fats and oils such as processed [[linseed oil]], [[tung oil]], and [[castor oil]], used in lubricants, paints, cosmetics, pharmaceuticals, and other industrial purposes. Although thought of as [[ester]]s of [[glycerin]] and a varying blend of [[fatty acid]]s, in fact these oils contain free fatty acids and [[diglyceride]]s as well.
== Uses of triglyceride vegetable oil ==
Oils extracted from plants have been used in many cultures, since ancient time. As an example, in a 4,000 year old "kitchen" unearthed in [[Indiana]]'s [[Charlestown State Park]], archaeologist Bob McCullough of [[Indiana University-Purdue University Fort Wayne|IPFW]] found evidence that natives used large slabs of rock to crush [[hickory nut]]s, then boiled them in water to extract the oil. <ref>{{cite web|url=http://www.stonepages.com/news/archives/001708.html|title=4,000-year-old 'kitchen' unearthed in Indiana|accessdate=2006-07-31}}</ref>
[[Fatty acids]] play an important role in the life and death of cardiac cells because they are essential fuels for mechanical and electrical activities of the heart. <ref>{{cite web | title=External blockade...by polyunsaturated fatty acids | url=http://www.pubmedcentral.nih.gov/pagerender.fcgi?artid=43279&pageindex=1#page | format= | publisher=pubmed | accessdate=2007-01-18}} - see page 1 of this link</ref> <ref>{{cite web | title=Antiarrhythmic effects of omega-3 fatty acids | url=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16919517&query_hl=87&itool=pubmed_DocSum | format= | publisher=pubmed | accessdate=2007-01-18}}</ref> <ref>{{cite web | title=Alpha-linolenic acid, cardiovascular disease and sudden death | url=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17086218&query_hl=3&itool=pubmed_DocSum | format= | publisher=pubmed | accessdate=2007-01-18}}</ref> <ref>{{cite web | title=Omega-3 and health | url=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17091903&query_hl=3&itool=pubmed_DocSum | format= | publisher=pubmed | accessdate=2007-01-18}}</ref>
=== Culinary uses ===
{{See also|Cooking oil}}
Many vegetable oils are consumed directly, or used directly as ingredients in food - a role that they share with some [[fat|animal fats]], including [[butter]] and [[ghee]]. The oils serve a number of purposes in this role:
* '''Texture''' - oils can serve to make other ingredients stick together less.
* '''Flavor''' - while less-flavorful oils command premium prices, oils such as [[olive oil]] or [[almond oil]] may be chosen specifically for the flavor they impart.
* '''Flavor base''' - oils can also "carry" flavors of other ingredients, since many flavors are present in chemicals that are soluble in oil.
Secondly, oils can be heated, and used to cook other foods. Oils that are suitable for this purpose must have a high [[flash point]]. Such oils include the major cooking oils - [[canola oil|canola]], [[sunflower oil|sunflower]], [[safflower oil|safflower]], [[peanut oil|peanut]] etc. Some oils, including [[rice bran oil]], are particularly valued in [[Asia|Asian]] cultures for high temperature cooking, because of their unusually high flash point.
=== Hydrogenated oils ===
[[Triglyceride]]-based vegetable fats and oils can be transformed through partial or complete '''[[hydrogenation]]''' into fats and oils of higher melting point. The [[hydrogenation]] process involves ''"[[#Sparging|sparging]]"'' the oil at high temperature and pressure with [[hydrogen]] in the presence of a [[catalyst]], typically a powdered [[nickel]] compound. As each double-bond in the [[triglyceride]] is broken, two hydrogen atoms form single bonds. The elimination of double-bonds by adding hydrogen atoms is called ''[[saturated fat|saturation]]''; as the degree of [[saturated fat|saturation]] increases, the oil progresses towards being fully hydrogenated. An oil may be hydrogenated to increase resistance to [[Rancidification|rancidity]] ([[oxidation]]) or to change its physical characteristics. As the degree of saturation increases, the oil's viscosity and melting point increase.
The use of [[saturated fat|hydrogenated oils]] in foods has never been completely satisfactory. Because the center arm of the [[triglyceride]] is shielded somewhat by the end [[triglyceride]]s, most of the [[hydrogenation]] occurs on the end [[triglyceride]]s. This makes the [[saturated fat|resulting fat]] more brittle. A margarine made from naturally more saturated tropical oils will be more plastic (more "spreadable") than a margarine made from hydrogenated soy oil. In addition, partial hydrogenation results in the formation of [[trans fats]], which have increasingly been viewed as unhealthy since the 1970s.
''(In the U.S., the [[United States Department of Agriculture|USDA]] ''[[Standard of Identity]]'' for a product labeled as ''vegetable oil margarine'' specifies that only canola, safflower, sunflower, corn, soybean, or peanut oil may be used.<ref>{{cite web
| url=http://www.ams.usda.gov/dairy/vegoil.pdf#search=%22%22standard%20of%20identity%22%20margarine%22
| title=USDA Standard of Identity
}} </ref> Products not labeled ''vegetable oil margarine'' do not have that restriction.)''
=== Industrial uses ===
Vegetable oils are used as an ingredient or component in many manufactured products.
* Many vegetable oils are used to make [[soap]]s, skin products, [[candle]]s, [[perfume]]s and other personal care and [[cosmetics|cosmetic products]].
* Some oils are particularly suitable as [[drying agent]]s, and are used in making [[paint]]s and other wood treatment products. [[Dammar oil]] (a mixture of linseed oil and [[dammar]] resin), for example, is used almost exclusively in treating the hulls of wooden boats.
* Vegetable oils are increasingly being used in the electrical industry as [[Electrical insulation|insulator]]s as vegetable oils are non-toxic to the environment, [[biodegradable]] if spilled and have high [[flash point|flash]] and fire points. However, vegetable oils have issues with chemical stability (there has to be a tradeoff with biodegradability), so they are generally used in systems where they are not exposed to [[oxygen]] and are more expensive than [[crude oil]] [[distillate]]. Two examples are [http://www.cooperpower.com/Products/Dielectric/EnvirotempFR3 FR3] by Cooper Power and [http://library.abb.com/GLOBAL/SCOT/scot252.nsf/VerityDisplay/C1256B3C00492DA685256C85006D74DC/$File/1LUS471050-LTE_BIO.PDF Biotemp] by ABB. [http://www.midel.com/ Midel 7131] by M & I materials is a synthetic tetraester, like a vegetable oil but with four fatty acid chains compared to the normal three found in a natural ester, and is manufactured by an alcohol plus acid reaction. Tetraesters generally have high stability to oxidation and have found use as engine lubricants.
* Vegetable oil is being used to produce bio-degradable [[hydraulic fluid]]<ref>{{cite web
| url=http://www.ars.usda.gov/is/pr/2000/000419.htm
| author=Linda McGraw
| title=Biodegradable Hydraulic Fluid Nears Market
| publisher=USDA
| date=April 19, 2000
| accessdate=2006-09-29
}}</ref>and [[lubricant]].<ref>
{{cite web
| url=http://www.gwrranci.org/gallery/20060824/
| title=Cass Scenic Railroad, West Virginia
| publisher=GWWCA
| accessdate=2007-07-03
}}</ref>
* Common vegetable oil has also been used experimentally as a cooling agent in PCs.
One limiting factor in industrial uses of vegetable oils is that all such oils eventually chemically decompose turning [[Rancidification|rancid]]. Oils that are more stable, such as [[Ben oil]] or [[mineral oil]], are preferred for some industrial uses.
Vegetable-based oils, like [[castor oil]], have been used as medicine and as lubricants for a long time. Castor oil has numerous industrial uses, primarily due to the presence of [[hydroxyl]] groups on the fatty acid chains. Castor oil, and other vegetable oils which have been chemically modified to contain hydroxyl groups, are becoming increasingly important in the production of [[polyurethane]] plastic for many applications. These modified vegetable oils are known as [[natural oil polyols]].
=== Pet food additive ===
Vegetable oil is used in production of some [[pet food]]s. [[AAFCO]] defines vegetable oil, in this context, as the product of vegetable origin obtained by extracting the oil from [[seed]]s or [[fruit]]s which are processed for edible purposes. In some poorer grade pet foods, the oil is listed only as "vegetable oil", without specifying the particular oil. <ref>{{cite web
| url=http://www.dogfoodproject.com/index.php?page=badingredients
| title= Ingredients to avoid
| publisher=The Dog Food Project
| accessdate=2007-06-26
}}</ref>
=== Fuel ===
{{main|Vegetable oil used as fuel}}
Vegetable oils are also used to make [[biodiesel]], which can be used like conventional [[diesel]]. Some [[vegetable oil blends]] are used in unmodified vehicles but [[straight vegetable oil]], also known as [[pure plant oil]], needs specially prepared vehicles which have a method of heating the oil to reduce its [[viscosity]]. The [[vegetable oil economy]] is growing and the availability of [[biodiesel around the world]] is increasing.
==Extraction==
The "modern" way of processing vegetable oil is by chemical extraction, using solvent extracts, which produces higher yields and is quicker and less expensive. The most common solvent is petroleum-derived [[hexane]]. This technique is used for most of the "newer" industrial oils such as soybean and corn oils.
Another way is physical extraction, which does not use solvent extracts. It is made the "traditional" way using several different types of mechanical extraction.<ref>{{cite web
| url=http://banglapedia.search.com.bd/HT/K_0050.htm
| title=Kalu (oil presser)
| publisher=Banglapedia
| accessdate=2006-11-12
}}</ref> This method is typically used to produce the more traditional oils (e.g., olive), and it is preferred by most "health-food" customers in the [[United States|USA]] and in [[Europe]]. [[Expeller]]-pressed extraction is one type, and there are two other types that are both oil presses: the [[screw press]] and the [[ram press (food)|ram press]]. Oil seed presses are commonly used in developing countries, among people for whom other extraction methods would be prohibitively expensive. <ref>{{cite web|url=http://www.attra.org/attra-pub/oilseed.html|title=Oilseed Processing for Small-Scale Producers|author=Janet Bachmann|accessdate=2006-07-31}}</ref> The amount of oil extracted using these methods varies widely, as shown in the following table for extracting [[mowrah butter]] in [[India]]:<ref>{{cite web
| work=Minor oil crops
| publisher=FAO
| title=Illipe
| author=B.L. Axtell from research by R.M. Fairman
| date=1992
| url=http://www.fao.org/es/faodef/fdef14e.htm
| accessdate=2006-11-12
}}</ref>
{| class="wikitable"
! Method !! Percentage extracted
|-
| Ghani<ref>{{cite web
| url=http://banglapedia.search.com.bd/HT/G_0089.htm
| title=Ghani
| publisher=Banglapedia
| accessdate=2006-11-12
}} A ghani is a traditional [[India]]n oil press, driven by a horse or ox.</ref> || 20-30%
|-
| Expellers || 34-37%
|-
| Solvent || 40-43%
|}
[[Supercritical carbon dioxide]] can also be used for the extraction purpose and is non toxic.<ref>{{cite journal|url=http://www.aocs.org/archives/am2005/session.asp?session=PRO+1%2FSOA+1%3A++Nutraceuticals%2FSpecialty+Oil+Processing|title=Pilot Scale Supercritical Carbon Dioxide Extraction and Characterization of Wheat Germ Oil|author=M. Eisenmenger, N. Dunford, F. Eller and S. Taylor|volume=96|date=2005|journal=AOCS Proceedings}}</ref>
==Production==
Crude oil, straight from the crushing operation, is not considered edible in the case of most oilseeds. The same is true for the remaining meal. For instance, animals fed raw soy meal will waste away, even though soy meal is high in protein. Researchers at Central Soya discovered that a [[Trypsin inhibitor|trypsin inhibitor]] in soybeans could be deactivated by toasting the meal, and both licensed their invention, and sold soy meal augmented with vitamins and minerals as MasterMix, a product for farmers to mix with their own grain to produce a high quality feed.
The processing of soy oil is typical of that used with most vegetable oils. Crude soy oil is first mixed with caustic soda. [[Saponification]] turns free fatty acids into soap. The soap is removed with a [[centrifuge]]. Neutralized dry soap stock (NDSS) is typically used in animal feed, more to get rid of it than because it is particularly nourishing. The remaining oil is deodorized by heating under a near-perfect [[vacuum]] and [[#Sparging|sparged]] with water. The condensate is further processed to become vitamin E food supplement, while the oil can be sold to manufacturers and consumers at this point.
Some of the oil is further processed. By carefully filtering the oil at near-freezing temperatures, "winter oil" is produced. This oil is sold to manufacturers of salad dressings, so that the dressings do not turn cloudy when refrigerated.
The oil may be partially [[hydrogenation|hydrogenated]] to produce various ingredient oils. Lightly hydrogenated oils have very similar physical characteristics to regular soy oil, but are more resistant to becoming rancid.
[[Margarine]] oils need to be mostly solid at 32 °C (90 °F) so that the margarine does not melt in warm rooms, yet it needs to be completely liquid at 37 °C (98 °F), so that it doesn't leave a "lardy" taste in the mouth.
Another major use of soy oil is for fry oils. These oils require substantial hydrogenation to keep the polyunsaturates of soy oil from becoming rancid.
Hardening vegetable oil is done by raising a blend of vegetable oil and a catalyst in near-vacuum to very high temperatures, and introducing hydrogen. This causes the carbon atoms of the oil to break double-bonds with other carbons, each carbon forming a new single-bond with a hydrogen atom. Adding these hydrogen atoms to the oil makes it more solid, raises the [[smoke point]], and makes the oil more stable.
Hydrogenated vegetable oils differ in two major ways from other oils which are equally saturated. During hydrogenation, it is easier for hydrogen to come into contact with the fatty acids on the end of the triglyceride, and less easy for them to come into contact with the center fatty acid. This makes the resulting fat more brittle than a tropical oil; soy margarines are less "spreadable". The other difference is that trans fatty acids (often called [[trans fat]]) are formed in the hydrogenation reactor, and may amount to as much as 40 percent by weight of a partially hydrogenated oil. Trans acids are increasingly thought to be unhealthy.
===Sparging===
In the processing of edible oils, the oil is heated under vacuum to near the smoke point, and water is introduced at the bottom of the oil. The water immediately is converted to steam, which bubbles through the oil, carrying with it any chemicals which are water-soluble. The steam sparging removes impurities that can impart unwanted flavors and odors to the oil.
== Particular oils ==
{{mainlist|List of vegetable oils}}
The following triglyceride vegetable oils account for almost all world-wide production, by volume. All are used as both cooking oils and as [[SVO]] or to make [[biodiesel]]. According to the USDA, the total world consumption of major vegetable oils in 2000 was:
{| class="sortable wikitable"
! Oil source
! World consumption<br/>(million [[tons]])
! Notes
|-
| [[Soybean]] || align="center" | 26.0 || Accounts for about half of worldwide edible oil production.
|-
| [[Palm Oil|Palm]] || align="center" | 23.3 || The most widely produced [[tropical]] oil. Also used to make [[biofuel]].
|-
| [[Rapeseed]] || align="center" | 13.1 || One of the most widely used cooking oils, [[Canola]] is a (trademarked) variety ([[cultivar]]) of rapeseed.
|-
| [[Sunflower seed]] || align="center" | 8.6 || A common cooking oil, also used to make [[biodiesel]].
|-
| [[Peanut]] || align="center" | 4.2 || [[Peanut oil]] Mild-flavored cooking oil.
|-
| [[Cottonseed]] || align="center" | 3.6 || A major food oil, often used in industrial food processing.
|-
| [[Palm Kernel]] || align="center" | 2.7 || From the [[seed]] of the African palm tree
|-
| [[Olive Oil|Olive]] || align="center" | 2.5 || Used in [[cooking]], [[cosmetics]], [[soaps]] and as a [[fuel]] for traditional [[oil lamps]]
|}
Note that these figures include industrial and animal feed use. The majority of European rapeseed oil production is used to produce [[biodiesel]], or used directly as fuel in [[diesel]] cars which may require modification to heat the oil to reduce its higher [[viscosity]]. The suitability of the fuel should come as little surprise, as [[Rudolf Diesel]] originally designed his engine to run on [[peanut oil]].
Other significant triglyceride oils include:
* [[Corn oil]], one of the most common, and inexpensive cooking oils.
* [[Hazelnut oil|Hazelnut]] and other nut oils
* [[Linseed oil]], from [[flax]] seeds
* [[Rice bran oil]], from [[rice]] grains
* [[Safflower oil]], a flavorless and colorless cooking oil.
* [[Sesame oil]], used as a cooking oil, and as a massage oil, particularly in [[India]].
==History of edible vegetable oils in North America==
While olive oil and other pressed oils have been around for millennia, [[Procter & Gamble]] researchers were innovators when they started selling cottonseed oil as a creamed shortening, in 1911. [[Ginning mill]]s were happy to have someone haul away the cotton seeds. Procter & Gamble researchers learned how to extract the oil, refine it, partially hydrogenate it (causing it to be solid at room temperature and thus mimic natural lard), and can it under nitrogen gas. Compared to the rendered lard Procter & Gamble was already selling to consumers, [[Crisco]] was cheaper, easier to stir into a recipe, and could be stored at room temperature for two years without turning rancid. (Procter & Gamble sold their fats and oils brands - ''Jif'' and ''Crisco'' - to [[Smuckers|The J.M. Smucker Co.]] in 2002.)
Soybeans were an exciting new crop from [[China]] in the 1930s. Soy was protein-rich, and the light tasteless oil was extremely high in polyunsaturates. [[Henry Ford]] established a soybean research laboratory, developed soybean plastics and a soy-based synthetic wool, and built a car ''almost entirely'' out of soybeans.<ref>{{cite web
| url=http://www.thehenryford.org/research/services/populartopics/SoybeanCar/default.asp
| title=Soybean Car
| work=Popular Research Topics
| publisher=Benson Ford Research Center
| accessdate=2006-10-23
}}</ref> Roger Drackett had a successful new product with [[Windex]], but he invested heavily in soybean research, seeing it as a smart investment.<ref>{{cite news
| url=http://www.cincypost.com/living/1999/drack052199.html
| title=Philip W. Drackett: Earned profits, plaudits
| work=[[The Cincinnati Post]]
| publisher=[[E. W. Scripps Company]]
| author=Barry M. Horstman
| first=Barry M
| last=Horstman
| date=1999-05-21
| accessdate=2006-10-22
| archiveurl=http://web.archive.org/web/20051205202014/http://www.cincypost.com/living/1999/drack052199.html
| archivedate=2005-12-05
}}</ref> By the 1950s and 1960s, soybean oil had become the most popular vegetable oil in the US.
In the mid-1970s, Canadian researchers developed a low-erucic rapeseed cultivar. Because the word "rape" was not considered optimal for marketing, they coined the name "canola" (from "Canada Oil"). The [[Food and Drug Administration|FDA]] approved use of the canola name in January 1985,<ref>{{cite web|url=http://www.fda.gov/bbs/topics/ANSWERS/ANS00198.html|title=Canola oil|accessdate=2006-07-31}}</ref> and U.S. farmers started planting large areas that spring. Canola oil is lower in saturated fats, and higher in mono-unsaturates and is a better source of [[omega-3]] fats than other popular oils. Canola is very thin (unlike corn oil) and flavorless (unlike olive oil) so it largely succeeds by displacing soy oil, just as soy oil largely succeeded by displacing cottonseed oil.
==Waste oil==
As of 2000, the [[United States]] were producing in excess of 11 billion liters of waste vegetable oil annually, mainly from industrial [[deep fryer]]s in [[potato]] processing plants, [[snack food]] factories and [[fast food restaurant]]s.
Waste vegetable oil, sold as the commodity [[yellow grease]] has a [[market value]] of approximately [[USD|$]]1.09 per US [[gallon]] ($0.29/l or $335 per [[tonne|metric tonne]]), expected to rise to $1.21 by 2013, enough to make collection economically viable.<ref>{{cite web|url=http://tonto.eia.doe.gov/FTPROOT/environment/biodiesel.pdf|format=PDF|title=Biodiesel Performance, Costs, and Use|author=Anthony Radich|accessdate=2006-07-31}}</ref>
Currently, the largest uses of waste vegetable oil in the U.S. are for [[animal feed]], [[pet food]], and [[cosmetics]]. Since 2002, an increasing number of [[European Union]] countries have prohibited the inclusion of [[waste]] vegetable oil from [[catering]] in animal feed. Waste cooking oils from food manufacturing, however, as well as fresh or unused cooking oil, continues to be used in animal feed. <ref>{{cite web|url=http://www.food.gov.uk/foodindustry/guidancenotes/foodguid/wastecookingoil|title=Waste cooking oil from catering premises|accessdate=2006-07-31}}</ref>
==See also==
* [[Algae culture]]
* [[Biodiesel]]
* [[Cooking oil]]
* [[Decorticator]]
* [[Deodoriser]]
* [[Essential oils]]
* [[Expeller]]
* [[Extruder]]
* [[Fatty Acid]]
* [[Fragrance oil]]
* [[Lipid]]
* [[List of macerated oils]]
* [[List of vegetable oils]]
* [[Mill (factory)|Mill]]
* [[Non food crops]]
* [[Oleochemistry]]
* [[Straight vegetable oil|Straight vegetable oil (SVO)]]
* [[Vernonia oil]]
== Notes and references ==
{{reflist|2}}
==Other references==
<div class="references-2column">
* Beare-Rogers, J.L. 1983. "Trans and positional isomers of common fatty acids." In H.H. Draper (ed.) ''Advances in Nutritional Research''. Vol. 5 Plenum Press, New York, pp. 171-200.
* Berry, E.M. and Hirsch, J. 1986. "Does dietary linolenic acid influence blood pressure?" ''American Journal of Clinical Nutrition''. 44: 336-340.
* Beyers, E.C. and Emken, E.A. 1991. "Metabolites of cis, trans, and trans, cis isomers of linoleic acid in mice and incorporation into tissue lipids." ''Biochimica et Biophysica Acta''. 1082: 275-284.
* Birch, D.G., Birch, E.E., Hoffman, D.R., and Uauy, R.D. 1992. "Retinal development in very-low-birth-weight infants fed diets differing in omega-3 fatty acids." ''Investigative Ophthalmology and Visual Science'' 33(8): 2365-2376.
* Birch, E.E., Birch, D.G., Hoffman, D.R., and Uauy, R. 1992. "Dietary essential fatty acid supply and visual acuity development." ''Investigative Ophthalmology and Visual Science''. 33(11): 3242-3253.
* Brenner, R.R. 1989. ''Factors influencing fatty acid chain elongation and desaturation, in the role of fats in human nutrition.'' 2nd edn. (eds A.J. Vergroesen and M. Crawford), Academic Press, London pp. 45-79.
* British Nutrition Foundation. 1987. ''Report of the task force on trans fatty acids.'' London: British Nutrition Foundation.
* ''Central Soya annual report'', 1979.
* Emken, E. A. 1984. "Nutrition and biochemistry of trans and positional fatty acid isomers in hydrogenated oils." ''Annual Reviews of Nutrition''. 4: 339-376.
* Enig, M.G., Atal, S., Keeney, M and Sampugna, J. 1990. "Isomeric trans fatty acids in the U.S. diet." ''Journal of the American College of Nutrition''. 9: 471-486.
* Ascherio, A., Hennekens, C.H., Baring, J.E., Master, C., Stampfer, M.J. and Willett, W.C. 1994. "Trans fatty acids intake and risk of myocardial infarction." ''Circulation''. 89: 94-101.
* Gurr, M.I. 1983. "Trans fatty acids: Metabolic and nutritional significance." ''Bulletin of the International Dairy Federation''. Document 166: 5-18.
* Hui Y. H., editor, "Bailey's Industrial Oil and Fat Products," ''Edible Oil and Fat Products''
* Koletzko, B. 1992. "Trans fatty acids may impair biosynthesis of long-chain polyunsaturates and growth in man." ''Acta Paediatrica''. 81: 302-306.
* Lief, Alfred, ''It floats: The story of Procter & Gamble'', published 1958 by Rinehart.
* MacMillen, Harold W., ''Mr. Mac and Central Soya: the foodpower story,'' published 1967 by Newcomen Society
* Marchand, C.M. 1982. "Positional isomers of trans-octadecenoic acids in margarine." ''Canadian Institute of Food Science and Technology Journal''. 15: 196-199.
* Mensink, R.P., Zock, P.L., Katan, M.B. and Hornstra, G. 1992. "Effect of dietary cis-and trans-fatty acids on serum lipoprotein[a] levels in humans." ''Journal of Lipid Research''. 33: 1493-1501.
* Siguel, E.N. and Lerman, R.H. 1993. "Trans fatty acid patterns in patients with angiographically documented coronary artery disease." ''American Journal of Cardiology''. 71: 916-920.
* Troisi, R., Willett, W.C. and Weiss, S.T. 1992. "Trans-fatty acid intake in relation to serum lipid concentrations in adult men." ''American Journal of Clinical Nutrition''. 56: 1019-1024.
* Willett, W.C., Stampfer, M.J., Manson, J.E., Colditz, G.A., Speizer, F.E., Rosner, B.A., Sampson, L.A. and Hennekens, C.H. 1993. "Intake of trans fatty acids and risk of coronary heart disease among women." ''The Lancet''. 341: 581-585.
</div>
== External links ==
* {{cite web
| url=http://www.hydrosafe.com/
| title=Hydro Safe Biodegradable Oil
| publisher=Hydrosafe
}}
* {{cite web
| url=http://www.hyfoma.com/en/content/food-branches-processing-manufacturing/oil-margarines-sauces/oil-fats/process_description.html
| title=Edible Oils
| publisher=[[Hyfoma]]
| accessdate=2006-11-05
}}
* {{cite web
| url=http://journeytoforever.org/biodiesel_yield.html
| title=Oil yields and characteristics
| publisher=Journey to forever
| accessdate=2006-11-05
}}
* {{cite web
| url=http://www.vegetableoildiesel.co.uk/forum/index.php
| title=Vegetable oils as fuel forum
| publisher=UK Goat Industries
| accessdate=2006-11-05
}}
* {{cite web
| url=http://www.nnfcc.co.uk/products/oil/oindex.cfm
| publisher=National Non Food Crops Centre
| title=Oil Crops
| accessdate=2006-11-05
}} Information on the use of vegetable oils in fuel, lubricants, polymers, solvents and surfactants.
[[Category:Vegetable oils| ]]
[[Category:Cooking fats]]
[[Category:Viscosity]]
[[Category:Oils]]
[[Category:Pet foods]]
[[af:Plantaardige olie]]
[[bg:Растително масло]]
[[cs:Rostlinný olej]]
[[da:Vegetabilsk olie]]
[[de:Pflanzenöl]]
[[es:Aceite vegetal]]
[[et:Taimerasv]]
[[fi:Kasviöljy]]
[[fr:Huile alimentaire]]
[[it:Olio vegetale]]
[[lt:Augalinis aliejus]]
[[nl:Plantaardige olie]]
[[pl:Olej roślinny]]
[[ru:Растительное масло]]
[[simple:Vegetable oil]]
[[sv:Matolja]]
[[th:น้ำมันพืช]]
* [http://www.greasology.org/ Biofuel Tutorial] - Free tutorial on using vegetable oil as diesel fuel