Soybean oil is a vegetable oil extracted from the seeds of the soybean (Glycine max). It is one of the most widely consumed cooking oils. As a drying oil, processed soybean oil is also used as a base for printing inks (soy ink) and oil paints.
To produce soybean oil, the soybeans are cracked, adjusted for moisture content, heated to between 60 and 88 ºC (140–190 °F), rolled into flakes, and solvent-extracted with hexanes. 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 tons 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.
Per 100g, soybean oil has 16g of saturated fat, 23g of mono-unsaturated fat, and 58g of poly-unsaturated fat. The major unsaturated fatty acids in soybean oil triglycerides are the poly-unsaturates, alpha-linolenic acid (C-18:3), 7-10%, and linoleic acid (C-18:2), 51%; and the mono-unsaturate, oleic acid (C-18:1), 23%. It also contains the saturated fatty acids, stearic acid, (C-18:0), 4%, and palmitic acid, (c-16:0), 10%.
The high-proportion of oxidation-prone linolenic acid is undesirable for some uses, such as cooking oils. Three companies, Monsanto Company, DuPont/Bunge, and Asoyia in 2004 introduced low linolenic Roundup Ready soybeans. In the past, hydrogenation was used to reduce the unsaturation in linolenic acid, but this produced the unnatural trans-fatty acid configuration, whereas in nature the configuration is cis.
Comparison to other vegetable oils 
|Polyunsaturated fatty acids||Oleic acid
|Total poly||linolenic acid
|Canola (rapeseed)||7.365||63.276||28.142||-||-||-||400 °F (204 °C)|
|Coconut||91.00||6.000||3.000||-||2||6||350 °F (177 °C)|
|Corn||12.948||27.576||54.677||1||58||28||450 °F (232 °C)|
|Cottonseed||25.900||17.800||51.900||1||54||19||420 °F (216 °C)|
|Flaxseed/Linseed (European)||6 - 9||10 - 22||68 - 89||56 - 71||12 - 18||10 - 22||225 °F (107 °C)|
|Olive||14.00||72.00||14.00||-||-||-||380 °F (193 °C)|
|Palm||49.300||37.000||9.300||-||10||40||455 °F (235 °C)|
|Peanut||16.900||46.200||32.000||-||32||48||437 °F (225 °C)|
|8.00||15.00||75.00||-||-||-||410 °F (210 °C)|
|7.541||75.221||12.820||-||-||-||410 °F (210 °C)|
|Soybean||15.650||22.783||57.740||7||54||24||460 °F (238 °C)|
|10.100||45.400||40.100||0.200||39.800||45.300||440 °F (227 °C)|
|9.859||83.689||3.798||-||-||-||440 °F (227 °C)|
|Values as percent (%) by weight of total fat.|
- This table needs to be amended - olive oil is rich in oleic acid***
|Total fat||Saturated fat||Monounsaturated fat||Polyunsaturated fat||Smoke point|
|Sunflower oil||100g||11g||20g (84g in high oleic variety)||69g (4g in high oleic variety)||225 °C (437 °F)|
|Soybean oil||100g||16g||23g||58g||257 °C (495 °F)|
|Canola oil||100g||7g||63g||28g||205 °C (401 °F)|
|Olive oil||100g||14g||73g||11g||190 °C (374 °F)|
|Corn oil||100g||15g||30g||55g||230 °C (446 °F)|
|Peanut oil||100g||17g||46g||32g||225 °C (437 °F)|
|Rice bran oil||100g||25g||38g||37g||213 °C (415 °F)|
|Vegetable shortening (hydrogenated)||71g||23g (34%)||8g (11%)||37g (52%)||165 °C (329 °F)|
|Lard||100g||39g||45g||11g||190 °C (374 °F)|
|Suet||94g||52g (55%)||32g (34%)||3g (3%)||200°C (400°F)|
|Butter||81g||51g (63%)||21g (26%)||3g (4%)||150 °C (302 °F)|
Drying oil 
Soybean oil is a drying oil, which means that it will slowly harden 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.
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 oils 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.
- United States Department of Agriculture, Agricultural Statistics 2004. Table 3-51.
- Poth, U. (2001). "Drying Oils and Related Products". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a09_055. ISBN 3527306730.
- Oil, soybean, salad or cooking
- "Nutrient database, Release 24". United States Department of Agriculture. All values in this column are from the USDA Nutrient database unless otherwise cited.
- "Fats, Oils, Fatty Acids, Triglycerides". Scientific Psychic (R). All values for ω-3, ω-6, ω-9 fats (not hydrogenated) are from Scientific Psychic (R) unless otherwise cited.
- Katragadda, H. R.; Fullana, A. S.; Sidhu, S.; Carbonell-Barrachina, Á. A. (2010). "Emissions of volatile aldehydes from heated cooking oils". Food Chemistry 120: 59. doi:10.1016/j.foodchem.2009.09.070.
- Wolke, Robert L. (May 16, 2007). "Where There's Smoke, There's a Fryer". The Washington Post. Retrieved March 5, 2011.
- Fatty acid composition of important plant and animal fats and oils (German) 21 December 2011, Hans-Jochen Fiebig, Münster
- (Italian) Scheda tecnica dell'olio di palma bifrazionato PO 64.
- The Culinary Institute of America (2011). The Professional Chef. New York: Wiley. ISBN 0-470-42135-5.
- Barnard DR, Xue RD (Jul 2004). "Laboratory evaluation of mosquito repellents against Aedes albopictus, Culex nigripalpus, and Ochierotatus triseriatus (Diptera: Culicidae)". J Med Entomol. 41 (4): 726–30. doi:10.1603/0022-2585-41.4.726. PMID 15311467.
- Fradin MS, Day JF (Jul 2002). "Comparative efficacy of insect repellents against mosquito bites". N Engl J Med. 347 (1): 13–8. doi:10.1056/NEJMoa011699. PMID 12097535.