is a vegetable oil
extracted from the seeds of the soybean
). It is one of the most widely consumed cooking oil
s. As a drying oil
, processed soybean oil is also used as a base for printing ink
s ( soy ink
) and oil paint
Chinese records dating prior to 2000 B.C. mention use of cultivated soybeans to produce edible soy oil. Ancient Chinese literature reveals that soybeans were extensively cultivated and highly valued as a use for the soybean oil production process before written records were kept.
To produce soybean oil, the soybeans are cracked, adjusted for moisture content, heated to between 60 and 88 °C (140–190 °F), rolled into flakes, and solvent-extracted with hexane
s. The oil is then refined, blended for different applications, and sometimes hydrogenated
. Soybean oils, both liquid and partially hydrogenated are sold as "vegetable oil," or are ingredients in a wide variety of processed foods. Most of the remaining residue ( soybean meal
) is used as animal feed.
In the 2002–2003 growing season, 30.6 million ton
s of soybean oil were produced worldwide, constituting about half of worldwide edible vegetable oil production, and thirty percent of all fats and oils produced, including animal fats and oils derived from tropical plants. United States Department of Agriculture
, Agricultural Statistics 2004
. Table 3-51.
Per 100 g, soybean oil has 16 g of saturated fat, 23 g of monounsaturated fat, and 58 g of polyunsaturated fat. Oil, soybean, salad or cooking
The major unsaturated
fatty acids in soybean oil triglycerides
are the polyunsaturates alpha-linolenic acid
(C-18:3), 7-10%, and linoleic acid
(C-18:2), 51%; and the monounsaturate oleic acid
(C-18:1), 23%. It also contains the saturated fatty acids stearic acid
(C-18:0), 4%, and palmitic acid
The high-proportion of oxidation-prone linolenic acid is undesirable for some uses, such as cooking oils. Three companies, Monsanto Company
, and Asoyia in 2004 introduced low linolenic Roundup Ready
may be used to reduce the unsaturation in linolenic acid. The resulting oil is called hydrogenated soybean oil. If the hydrogenation is only partially complete, the oil may contain small amounts of trans fat
The carcinogen N‐Nitrosodi-n-butylamine
has been measured in soybean oil at a concentration of 290 μg/kg, in cheese at 20 to 30 μg/kg, and in smoked or cured meats at up to 3.9 μg/kg. It has also been detected in tobacco smoke at a concentration of 3 ng per cigarette.http://ntp.niehs.nih.gov/ntp/roc/twelfth/profiles/Nitrosamines.pdf
Comparison to other vegetable oils
Soybean oil is mostly used for frying
. It is also used as a condiment
Soybean oil is one of many drying oil
s, which means that it will slowly harden (due to free-radical based polymerization) upon exposure to air, forming a flexible, transparent, and waterproof solid. Because of this property, it is used in some printing ink and oil paint
formulations. However, other oils (such as linseed oil
) may be superior for some drying oil applications.
Fixative for insect repellents
While soybean oil has no direct insect repellent
activity, it is used as a fixative
to extend the short duration of action of essential oil
s such as geranium oil
in several commercial products.
Soybean oil is traded at the Chicago Board of Trade
in contracts of 60,000 pounds at a time. Prices are listed in cents and hundredths of a cent per pound.