Soybean oil

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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.

Production[edit]

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.[1]

Composition[edit]

Per 100 g, soybean oil has 16 g of saturated fat, 23 g of monounsaturated fat, and 58 g of polyunsaturated fat.[2][3] 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%.[4] 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. Hydrogenation 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.

Comparison to other vegetable oils[edit]

Vegetable oils
Type Processing
Treatment
Saturated
fatty acids[5]
Mono-
unsaturated
fatty acids[5]
Polyunsaturated fatty acids Oleic acid
(ω-9)
Smoke point
Total poly[5] linolenic acid
(ω-3)
Linoleic acid
(ω-6)
Canola (rapeseed)   7.365 63.276 28.142 10 10   400 °F (204 °C)[6]
Coconut   91.00 6.000 3.000   2 6 350 °F (177 °C)[6]
Corn[7]   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)[7]
Flaxseed/Linseed (European)[8]   7.5 15.5 79 64 15 11 225 °F (107 °C)
Olive   14.00 72.00 14.00 1.5 15   380 °F (193 °C)[6]
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)[7]
Safflower (>70% linoleic)   8.00 15.00 75.00       410 °F (210 °C)[6]
Safflower (high oleic)   7.541 75.221 12.820       410 °F (210 °C)[6]
Soybean   15.650 22.783 57.740 7 50 24 460 °F (238 °C)[7]
Sunflower (<60% linoleic)   10.100 45.400 40.100 0.200 39.800 45.300 440 °F (227 °C)[7]
Sunflower (>70% oleic)   9.859 83.689 3.798       440 °F (227 °C)[7]
Cottonseed (hydrogenated)[5] Hydrogenated 93.600 1.529 .587   .287  
Palm (hydrogenated) Hydrogenated 47.500 40.600 7.500      
Soybean (hydrogenated)[5] Hydrogenated 21.100 73.700 .400 .096    
Values as percent (%) by weight of total fat.

Applications[edit]

Food[edit]

Soybean oil is mostly used for frying and baking. It is also used as a condiment for salads.

Comparative properties of common cooking fats (per 100 g)
Total fat Saturated fat Monounsaturated fat Polyunsaturated fat Smoke point
Sunflower oil 100 g 11 g (11%) 20 g (84 g in high oleic variety[5]) 69 g (4 g in high oleic variety[5]) 225 °C (437 °F)[10]
Soybean oil 100 g 16 g (16%) 23 g 58 g 257 °C (495 °F)[10]
Canola oil 100 g 7 g (7%) 63 g 28 g 205 °C (401 °F)[5][6]
Olive oil 100 g 14 g (14%) 73 g 11 g 190 °C (374 °F)[10]
Corn oil 100 g 15 g (15%) 30 g 55 g 230 °C (446 °F)[10]
Peanut oil 100 g 17 g (17%) 46 g 32 g 225 °C (437 °F)[10]
Rice bran oil 100 g 25 g (25%) 38 g 37 g 250 °C (482 °F)[11]
Vegetable shortening (hydrogenated) 71 g 23 g (34%) 8 g (11%) 37 g (52%) 165 °C (329 °F)[10]
Lard 100 g 39 g (39%) 45 g 11 g 190 °C (374 °F)[10]
Suet 94 g 52 g (55%) 32 g (34%) 3 g (3%) 200 °C (392 °F)
Butter 81 g 51 g (63%) 21 g (26%) 3 g (4%) 150 °C (302 °F)[10]
Coconut oil 100 g 86 g (86%) 6 g (6%) 2 g (2%) 177 °C (351 °F)

Drying oils[edit]

Soybean oil is one of many drying oils, 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[edit]

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.[12][13]

Trading[edit]

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.

References[edit]

  1. ^ United States Department of Agriculture, Agricultural Statistics 2004. Table 3-51.
  2. ^ Poth, U. (2001). "Drying Oils and Related Products". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a09_055. ISBN 3527306730.  edit
  3. ^ Oil, soybean, salad or cooking
  4. ^ Ivanov, Dušica S.; Lević, Jovanka D.; Sredanović, Slavica A. (2010). "Fatty acid composition of various soybean products". Journal of the Institute for Food Technology in Novi Sad 37 (2): 65–70. Retrieved 21 June 2013. 
  5. ^ a b c d e f g h "Nutrient database, Release 24". United States Department of Agriculture.  All values in this column are from the USDA Nutrient database unless otherwise cited.
  6. ^ a b c d e f 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.  edit
  7. ^ a b c d e f Wolke, Robert L. (May 16, 2007). "Where There's Smoke, There's a Fryer". The Washington Post. Retrieved March 5, 2011. 
  8. ^ Fatty acid composition of important plant and animal fats and oils (German) 21 December 2011, Hans-Jochen Fiebig, Münster
  9. ^ Scheda tecnica dell'olio di palma bifrazionato PO 64 (Italian)
  10. ^ a b c d e f g h The Culinary Institute of America (2011). The Professional Chef (9th ed.). Hoboken, New Jersey: John Wiley & Sons. ISBN 978-0-470-42135-2. OCLC 707248142. 
  11. ^ [[1]]
  12. ^ Barnard DR, Xue RD (Jul 2004). "Laboratory evaluation of mosquito repellents against Aedes albopictus, Culex nigripalpus, and Ochierotatus triseriatus (Diptera: Culicidae)". Journal of Medical Entomology 41 (4): 726–30. doi:10.1603/0022-2585-41.4.726. PMID 15311467. 
  13. ^ 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.