Cottonseed oil

Mississippi Cottonseed Oil Co. seed house, Jackson, Mississippi, USA

Cottonseed oil is a cooking oil extracted from the seeds of cotton plant of various species, mainly Gossypium hirsutum and Gossypium herbaceum. Cotton grown for oil extraction is one of the big four genetically modified crops grown around the world, next to soy, corn, and rapeseed (canola), mostly Monsanto products.^[1][2]

The cottonseed has a similar structure to other oilseeds such as sunflower seed, having an oil bearing kernel surrounded by a hard outer hull; in processing, the oil is extracted from the kernel. Cottonseed oil is used for salad oil, mayonnaise, salad dressing, and similar products because of its flavor stability.^[3] The cottonseed oil undergoes intensive treatment after extraction to reduce the level of gossypol found in untreated cottonseed oil, the consumption of which may produce undesirable side-effects.^[4]

Composition

Its fatty acid profile generally consists of 70% unsaturated fatty acids including 18% (13% - 44%) monounsaturated (oleic), and 52% (33.1%-60.1%) polyunsaturated (linoleic & linolenic).^[5]

Cottonseed oil is described by scientists as being "naturally hydrogenated" because the saturated fatty acids it contains are the natural myristic, palmitic, and (predominantly) stearic acids. These fatty acids make it a stable frying oil without the need for additional processing or the formation of trans fatty acids. Cotton seed oil is not required to be as fully hydrogenated for many purposes as some of the more polyunsaturated oils. On partial hydrogenation, the amounts of monounsaturated fatty acids actually increase. When hydrogenated to a typical iodine value of about 80, for example, its fatty acid profile shifts to 50% monounsaturated, 21% polyunsaturated, and 29% saturated, which are all well within current diet/health guidelines.^[3]

Gossypol is a toxic yellow polyphenolic compound produced by cotton and other members of the order Malvaceae, such as okra.^[6] This coloured compound is found in tiny glands in the seeds, leaf, stem, tap root bark, and root of the cotton plant. The adaptive function of the compound is believed to be one of facilitating insect resistance. Further, gossypol^{[Gossypol 1]} acts as a male and female contraceptive. It may be used to treat gynaecological problems and viral infections. In addition, global cotton seed production can potentially provide the protein requirements for half a billion people per year. Work is under way to find a viable solution to the gossypol^{[Gossypol 2]} problem.

The three key steps of refining, bleaching and deodorization that are involved in producing finished oil act to reduce the gossypol level. Ferric chloride is often used to decolorize cotton seed oil.^[7]

Nutrition

Cottonseed oil is under scrutiny by some nutritionists, who deem it too high in saturated fat and too low in monounsaturated fat.^[8] Detractors say that cottonseed oil may contain natural toxins and unacceptably high levels of pesticide residues, since "cotton is not classified as a food crop, and farmers use many agrichemicals when growing it."^[8] The natural toxin, gossypol, is eliminated in the refining process of commercially edible cottonseed oil, and the Food and Agriculture Organization of the United Nations has documented the ‘lack of appreciable residues in cottonseed and cottonseed oil.’^[9] Cottonseed oil has traditionally been used in foods such as potato chips and is a primary ingredient in Crisco, the shortening product.^[10] But since it is significantly less expensive than olive oil or canola oil, cottonseed has started to creep into a much wider range of processed foods, including cereals, breads and snack foods. Products that say "may contain one or more of these oils" and list cottonseed, virtually always contain it.^[11] Cottonseed oil resists rancidity and therefore offers a longer shelf life for food products in which it is an ingredient.

Physical properties

Once processed, cottonseed oil has a mild taste and appears generally clear with a light golden color, the amount of color depending on the amount of refining.^[12] Cottonseed oil has a relatively high smoke point as a frying medium. Like other long-chain fatty acid oils, cottonseed oil has a smoke point of about 450 °F (232 °C).^[6] Cottonseed oil is high in tocopherols which also contribute its stability giving products that contain it a long shelf life, hence manufacturers' proclivity to use it in packaged goods.

References

1. ^ "Reports on GM Canola". http://www.dpi.vic.gov.au/dpi/nrensr.nsf/LinkView/AE641E63162D0A50CA256ECA000A8B123A8D6D972510B1ED4A2567C40015A7EE.  from the Australian Department of Primary Industries.
2. ^ "Australian Department of Primary Industries homepage". http://www.dpi.vic.gov.au/. 
3. ^ ^{a b} "Twenty Facts About Cottonseed Oil". National Cottonseed Products Association. http://www.cottonseed.com/publications/facts.asp. 
4. ^ "Low potassium levels from use of Gossypol linked to paralysis". International Family Planning Perspectives 7 (1): 24–25. 1981. doi:10.2307/2947696. JSTOR 2947696. "Gossypol, a male antifertility agent derived from the cotton plant, may be the cause of hypokalemic paralysis in a small but significant proportion of its users." 
5. ^ "The Chemical and Functional Properties of Cottonseed Oil as a Deep-Fat Frying Medium". PhD Thesis, Darla Rachelle Daniel, Texas Tech University. http://etd.lib.ttu.edu/theses/available/etd-06272008-31295017084020/unrestricted/31295017084020.pdf. 
6. ^ ^{a b} Jones, Lynn A.; King, C. Clay (1996). "Cottonseed oil". In Y. H. Hui (ed.). Bailey's Industrial Oil and Fat Products, Edible Oil and Fat Products: Oils and Oilseeds. New York: Wiley. ISBN 978-0-471-59426-0. 
7. ^ "Research abstract: Southern Regional Research Laboratory". http://www.springerlink.com/content/h860k75388370033/. 
8. ^ ^{a b} Dr. Andrew Weil. "Why you should avoid cottonseed oil?". Q & A Library. http://www.drweil.com/drw/u/QAA400361/Is-Cottonseed-Oil-Okay.html. Retrieved 29 November 2010. 
9. ^ Edible Fats and oils: basic principles and modern practices, Daivd R. Erickson
10. ^ "Ingredient facts". crisco.com. http://www.crisco.com/Products/Details.aspx?groupID=17&prodID=803. 
11. ^ "Cottonseed oil use on the rise". cotton 247.com. http://www.cotton247.com/cg/?storyid=743. 
12. ^ "Cottonseed oil". National Cottonseed Products Association. http://www.cottonseedoiltour.com/pdf/NCPA_CSOFACTSHEET_03.pdf. Retrieved 29 November 2010. 

1. ^ "Gossypol". drugs.com. http://www.drugs.com/npp/gossypol.html. Retrieved 29 November 2010. 
2. ^ Engineering cottonseed for use in human nutrition by tissue-specific reduction of toxic gossypol. pnas.org. June 27, 2006. doi:10.1073/pnas.103.48.18054. 

External links

• Cottonseed oil production, supply, and distribution statistics by country - Sourced from the United States Department of Agriculture