Corn oil

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Corn oil, in a 5-liter plastic bottle
Corn oil, plastic jugs in cardboard boxes, 33 lbs. each

Corn oil (maize oil) is oil extracted from the germ of corn (maize). Its main use is in cooking, where its high smoke point makes refined corn oil a valuable frying oil. It is also a key ingredient in some margarines. Corn oil is generally less expensive than most other types of vegetable oils. One bushel of corn contains 1.55 pounds of corn oil (2.8% by weight). Corn agronomists have developed high-oil varieties; however, these varieties tend to show lower field yields, so they are not universally accepted by growers.

Corn oil is also a feedstock used for biodiesel. Other industrial uses for corn oil include soap, salve, paint, rustproofing for metal surfaces, inks, textiles, nitroglycerin, and insecticides. It is sometimes used as a carrier for drug molecules in pharmaceutical preparations.

Production[edit]

Almost all corn oil is expeller-pressed, then solvent-extracted using hexane or 2-methylpentane (isohexane).[1] The solvent is evaporated from the corn oil, recovered, and re-used. After extraction, the corn oil is then refined by degumming and/or alkali treatment, both of which remove phosphatides. Alkali treatment also neutralizes free fatty acids and removes color (bleaching). Final steps in refining include winterization (the removal of waxes), and deodorization by steam distillation of the oil at 232–260 °C (450–500 °F) under a high vacuum.[1]

Some specialty oil producers manufacture unrefined, 100%-expeller-pressed corn oil. This is a more expensive product since it has a much lower yield than the combination expeller and solvent process, as well as a smaller market share.

Constituents and comparison[edit]

Vegetable oils[2][3]
Type Processing
Treatment
Saturated
fatty acids
Monounsaturated fatty acids Polyunsaturated fatty acids Smoke point
Total mono[2] Oleic acid
(ω-9)
Total poly[2] linolenic acid
(ω-3)
Linoleic acid
(ω-6)
Avocado[4] 11.6 70.6 13.5 1 12.5 249 °C (480 °F)[5]
Canola[6] 7.4 63.3 61.8 28.1 9.1 18.6 238 °C (460 °F)[7]
Coconut[8] 82.5 6.3 6 1.7 175 °C (347 °F)[7]
Corn[9] 12.9 27.6 27.3 54.7 1 58

232 °C (450 °F)[10]

Cottonseed[11] 25.9 17.8 19 51.9 1 54 216 °C (420 °F)[10]
Flaxseed/Linseed[12] 9.0 18.4 18 67.8 53 13

107 °C (225 °F)

Olive[13] 13.8 73.0 71.3 10.5 0.7 9.8 193 °C (380 °F)[7]
Palm[14] 49.3 37.0 40 9.3 0.2 9.1 235 °C (455 °F)
Peanut[15] 20.3 48.1 46.5 31.5 31.4 232 °C (450 °F)[10]
Safflower[16] 7.5 75.2 75.2 12.8 0 12.8 212 °C (414 °F)[7]
Soybean[17] 15.6 22.8 22.6 57.7 7 51 238 °C (460 °F)[10]
Sunflower (< 60% linoleic)[18] 10.1 45.4 45.3 40.1 0.2 39.8

227 °C (440 °F)[10]

Sunflower (> 70% oleic)[19] 9.9 83.7 82.6 3.8 0.2 3.6

227 °C (440 °F)[10]

Cottonseed[20] Hydrogenated 93.6 1.5 0.6 0.3
Palm[21] Hydrogenated 88.2 5.7 0
Soybean[22] Partially hydrogenated 14.9 43.0 42.5 37.6 2.6 34.9
Values as percent (%) by weight of total fat.

See also[edit]

References[edit]

  1. ^ a b Corn Refiners Association. Corn Oil 5th Edition. 2006
  2. ^ a b c "US National Nutrient Database, Release 28". United States Department of Agriculture. May 2016.  All values in this column are from the USDA Nutrient database unless otherwise cited.
  3. ^ "Fats and fatty acids contents per 100 g (click for "more details") example: avocado oil; user can search for other oils". Nutritiondata.com, Conde Nast for the USDA National Nutrient Database, Standard Release 21. 2014. Retrieved 7 September 2017.  Values from Nutritiondata.com (SR 21) may need to be reconciled with most recent release from the USDA SR 28 as of Sept 2017.
  4. ^ "Avocado oil, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  5. ^ What is unrefined, extra virgin cold-pressed avocado oil?, The American Oil Chemists’ Society
  6. ^ "Canola oil, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  7. ^ a b c d 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. 
  8. ^ "Coconut oil, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  9. ^ "Corn oil, industrial and retail, all purpose salad or cooking, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  10. ^ 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. 
  11. ^ "Cottonseed oil, salad or cooking, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  12. ^ "Linseed/Flaxseed oil, cold pressed, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  13. ^ "Olive oil, salad or cooking, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  14. ^ "Palm oil, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  15. ^ Vegetable Oils in Food Technology (2011), p. 61.
  16. ^ "Safflower oil, salad or cooking, high oleic, primary commerce, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  17. ^ "Soybean oil, salad or cooking, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  18. ^ "Sunflower oil, less than 60% of total fats as linoleic acid, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  19. ^ "Sunflower oil, high oleic - 70% or more as oleic acid, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  20. ^ "Cottonseed oil, industrial, fully hydrogenated, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  21. ^ "Palm oil, industrial, fully hydrogenated, filling fat, fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  22. ^ "Soybean oil, salad or cooking, (partially hydrogenated), fat composition, 100 g". US National Nutrient Database, Release 28, United States Department of Agriculture. May 2016. Retrieved 6 September 2017. 
  23. ^ Daley, C.A.; Abbott, A.; Doyle, P.; Nader, G.; Larson, S. (2004). "A literature review of the value-added nutrients found in grass-fed beef products". California State University, Chico (College of Agriculture). Retrieved 2008-03-23. 
  24. ^ Yong Q. Chen; at al (2007). "Modulation of prostate cancer genetic risk by omega-3 and omega-6 fatty acids". The Journal of Clinical Investigation. 117 (7): 1866–1875. PMC 1890998Freely accessible. PMID 17607361. doi:10.1172/JCI31494. 

Further reading[edit]

  • Dupont J; PJ White; MP Carpenter; EJ Schaefer; SN Meydani; CE Elson; M Woods; SL Gorbach (October 1990). "Food uses and health effects of corn oil". J Am Coll Nutr. 9 (5): 438–470. PMID 2258533. 

External links[edit]