cottonseed oil

Background information

Cotton has long been known as nature's unique food and fiber plant. Cottonseed oil is extracted from the seeds of cotton plant (Gossypium hirsutum Linn). The cottonseed itself is very similar to other oilseeds such as sunflower seed, having an oil bearing kernel surrounded by a hard outer hull. The oil is extracted from the kernel. Cotton (oil) is also one of the big four (soy, corn, rapeseed/canola,^[1] and cotton) genetically modified crops grown around the world. Cottonseed oil is a favorite for salad oil, mayonnaise, salad dressing, and similar products because of its flavor stability. ^[2]

Chemical composition of cottonseed oil

Fatty acid profile of cottonseed oil

Cottonseed oil is among the most unsaturated oils. Others include corn, soybean, canola, safflower and sunflower seed oils. Cottonseed oil has a 2:1 ratio of polyunsaturated to saturated fatty acids. Its fatty acid profile generally consists of 70% unsaturated fatty acids including 18% monounsaturated (oleic), 52% polyunsaturated (linoleic) and 26% saturated (primarily palmitic and stearic). ^[3]

Cottonseed oil is described by scientists as being "naturally hydrogenated" because it contains high levels of oleic, palmitic, and stearic acids. These fatty acids make it a stable frying oil without the need for additional processing or the formation of trans fatty acids . Cottonseed 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. ^[4]

Tocopherols

Cottonseed oil is rich in tocopherols. These natural antioxidants, which have varying degrees of vitamin E activity, also contribute to its stability giving products that contain it a long life. Studies show that these natural antioxidants are retained at high levels in fried products, creating longer shelf life. ^[5]

Gossypol

Gossypol is a yellow poly phenolic compound produced by members of the order Malvaceae, which includes okra as well as cotton. ^[6][7][8] The pigment 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. Interest in gossypol in cottonseed oil is primarily based on recognition of gossypols role as a fertility control agent first seen in Chinese men. ^[9]

The three key steps of refining, bleaching and deodorization that are involved in producing finished oil each act to reduce the gossypol level. Refined, bleached, and deodorized (RBD) cottonseed oil, is available to the food industry and the customer in the United States, is a safe as well as nutritious vegetable oil. ^[10]

Refined, bleached and deodorized cottonseed oil is one of the purest food products available. Few foods can be as highly cleaned and refined, and still maintain their nutritional quality. ^[11][12]Like all major food crops, cottonseed production is regulated by food protection agencies of the Federal government and cottonseed oil meets the government's strict standards for purity. Researchers at Texas A&M University have genetically engineered cotton plants that contain very little gossypol in the seed, but still contain the compound in the stems and leaves. This provides protection against pests and diseases, while allowing the seed to be used for oil and meal for human consumption. The resulting gossypol-free cottonseed is then suitable as a high-quality protein source suitable for consumption not only by cattle, but also by humans, pigs, chickens, or turkeys, making the plant additionally valuable as a food crop.^[13]

Physical properties of cottonseed oil

It has a mild, nut like taste, non-oily consistency and generally clear with a light golden color, but the amount of color depends on the amount of refining.^[14] It has bland yet delicately appetizing oil free from a too strong cottonseed taste. ^[15][16] Cottonseed oil is stable enough to have a high smoke point as a frying medium, yet delicate enough to avoid coating a diner’s mouth when it’s used in salad dressings. Like other long-chain fatty acid oils, cottonseed oil with 0.01% free fatty acids has a smoke point of about 450 degrees Fahrenheit. ^[17]

Qualities that make cottonseed oil a good frying oil

Cottonseed oil makes a stable, natural frying oil without the need for additional hydrogenation. This avoids the formation of trans fatty acids. Cottonseed oil is described by scientists as "naturally hydrogenated" because of its levels of the different fatty acids. Like all vegetable oils, cottonseed oil is cholesterol free.^[18]

If hydrogenation is required to achieve a function, hydrogenating naturally saturated oil will produce fewer trans fatty acids. If a vegetable oil is hydrogenated to total saturation (less than 3.0 Iodine Value), there are no trans fatty acids left. Some food manufacturers use fully hydrogenated cottonseed oil blended with a high unsaturated oil to get a blend with near zero trans fatty acids. ^[19]

When hydrogenated to a typical Iodine Value of about 80, its fatty acid profile shifts to 50 percent monounsaturated, 21 percent polyunsaturated and 29 percent unsaturated; placing it well within current diet and health guidelines.^[20]

Cottonseed oil enhances, rather than masks, the fresh natural flavors of foods. Its neutral taste makes it perfect for frying seafood, snack foods and oriental foods, especially stir-fry. In snack foods, where oil becomes part of the product, cottonseed oil is recognized as being superior because of its low flavor reversion especially when used at high temperatures. And, toward the end of its useful life, cottonseed oil will not produce objectionable flavors as some oils do. ^[21]

Economics

Despite a 10-15% “premium” over the price of soybean oil traded on the Chicago Board of Trade (usually 3-5 cents), cottonseed oil provides an economic solution to the complex process of matching oils with foods to produce a finished product that is both satisfactory to consumers and economical for the processor. By eliminating or reducing the need for hydrogenation, cottonseed oil helps manufacturers save time and money associated with using this process. Because of its desirable stability, cottonseed oil deep frying oils do not have to be discarded as often. The turnover rate of frying oils used by manufacturers (e.g. chippers) can be up to 100% daily and up to 20-35% per day by food service operators. Due to the large quantities of foods that are fried, bulk amounts of cooking oil are removed continuously and must be replaced. Cottonseed oil lasts longer than many other oils, thus requiring less turnover and more cost savings.^[22] Cottonseed oil resists rancidity and therefore offers a longer shelf life for food products in which it is an ingredient.^[23]

Uses of cottonseed oil

1. As a cooking oil, it is used for frying in both commercial and home cooking. In shortening and margarine, it is ideal for baked food and cake icings. In the U. S., cottonseed oil is used primarily as a salad or cooking oil. About 56 percent of it is used for that purpose; 36 percent is used for baking and frying fats and the remainder for margarine and other uses.^[24]

2. Cottonseed oil is one of the most common oil in commercial frying in the production of potato and corn chips.^[25][26]

3. Cottonseed oil is used as cocoa butter substitutes after hydrogenation and/or fractionation. ^[27][28]

4. Hydrogenated Cottonseed oil is used in frozen desserts to replace butter fat. ^[29]

Versatility

1. Snack foods: Uniquely brings out natural flavor of potato chips and other snack foods.^[30]

2. Bakery: Stable in the beta prime crystal form, promoting a smooth, workable consistency. ^[31]

3. Asian foods: Perfect for sautéing and stir frying vegetables and seafood. ^[32]

4. Salad dressings: Sturdy, yet delicate enough to avoid coating a diner’s mouth.^[33]

5. Kosher for Passover- Cottonseed oil contains no animal byproducts and originates from cottonseed, rather than one of the five grains that are forbidden during the Passover. ^[34]

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. ^ National cottonseed products association website [1]
3. ^ http://www.ntokcotton.org/images/Cottonseed%20Oil%20Use.pdf
4. ^ National cottonseed products association website [2]
5. ^ http://www.cottonseed.com/publications/gmbroch.pdf
6. ^ Bailey’s Industrial Oil& Fat Products, Fifth Edition ,Volume 2 ; Edible oil and fat products: Oil and oil seeds–Cottonseed oil by Lynn A. Jones and C. Clay King
7. ^ http://botany.csdl.tamu.edu/FLORA/301Manhart/Dicots/Dillen/Mal/Mal.html
8. ^ http://en.wikipedia.org/wiki/Gossypol
9. ^ Bailey’s Industrial Oil& Fat Products, Fifth Edition ,Volume 2 ; Edible oil and fat products: Oil and oil seeds–Cottonseed oil by Lynn A. Jones and C. Clay King
10. ^ Bailey’s Industrial Oil& Fat Products, Fifth Edition ,Volume 2 ; Edible oil and fat products: Oil and oil seeds–Cottonseed oil by Lynn A. Jones and C. Clay King
11. ^ http://www.ntokcotton.org/images/Cottonseed%20Oil%20Use.pdf
12. ^ National cottonseed products association website http://www.cottonseed.com/publications/facts.asp
13. ^ http://en.wikipedia.org/wiki/Gossypol
14. ^ http://www.cottonseedoiltour.com/pdf/NCPA_CSOFACTSHEET_03.pdf
15. ^ http://www.cottonseed.com/publications/gmbroch.pdf
16. ^ http://www.welch-holme-clark.com/cottonseed_oil_-_refined_spec_.html
17. ^ Bailey’s Industrial Oil& Fat Products, Fifth Edition ,Volume 2 ; Edible oil and fat products: Oil and oil seeds–Cottonseed oil by Lynn A. Jones and C. Clay King
18. ^ http://www.welch-holme-clark.com/cottonseed_oil_-_refined_spec_.html
19. ^ http://www.ntokcotton.org/images/Cottonseed%20Oil%20Use.pdf
20. ^ National cottonseed products association website http://www.cottonseed.com/publications/facts.asp
21. ^ http://www.cottonseed.com/publications/gmbroch.pdf
22. ^ http://www.welch-holme-clark.com/cottonseed_oil_-_refined_spec_.html
23. ^ Bailey’s Industrial Oil& Fat Products, Fifth Edition ,Volume 2 ; Edible oil and fat products: Oil and oil seeds–Cottonseed oil by Lynn A. Jones and C. Clay King
24. ^ National cottonseed products association website http://www.cottonseed.com/publications/facts.asp
25. ^ Bailey’s Industrial Oil& Fat Products, Fifth Edition ,Volume 2 ; Edible oil and fat products: Oil and oil seeds–Cottonseed oil by Lynn A. Jones and C. Clay King
26. ^ National cottonseed products association website http://www.cottonseed.com/publications/facts.asp
27. ^ Bailey’s Industrial Oil& Fat Products, Fifth Edition ,Volume 2 ; Edible oil and fat products: Oil and oil seeds–Cottonseed oil by Lynn A. Jones and C. Clay King
28. ^ National cottonseed products association website http://www.cottonseed.com/publications/facts.asp
29. ^ Bailey’s Industrial Oil& Fat Products, Fifth Edition ,Volume 2 ; Edible oil and fat products: Oil and oil seeds–Cottonseed oil by Lynn A. Jones and C. Clay King
30. ^ http://www.cottonseedoiltour.com/pdf/NCPA_CSOFACTSHEET_03.pdf
31. ^ http://www.cottonseedoiltour.com/pdf/NCPA_CSOFACTSHEET_03.pdf
32. ^ http://www.cottonseedoiltour.com/pdf/NCPA_CSOFACTSHEET_03.pdf
33. ^ http://www.cottonseedoiltour.com/pdf/NCPA_CSOFACTSHEET_03.pdf
34. ^ http://www.cottonseedoiltour.com/pdf/NCPA_CSOFACTSHEET_03.pdf

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