Cottonseed oil is cooking oil from the seeds of cotton plants of various species, mainly Gossypium hirsutum and Gossypium herbaceum, that are grown for cotton fiber, animal feed, and oil.
Cotton seed 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.
Composition
Its fatty acid profile generally consists of 70% unsaturated fatty acids (18% monounsaturated, and 52% polyunsaturated), 26% saturated fatty acids. When it is fully hydrogenated, its profile is 94% saturated fat and 2% unsaturated fatty acids (1.5% monounsaturated, and 0.5% polyunsaturated). According to the National Cottonseed Products Association, cottonseed oil does not need to be hydrogenated as much as other polyunsaturated oils to achieve similar results.
Gossypol is a toxic, yellow, polyphenolic compound produced by cotton and other members of the order Malvaceae, such as okra. This naturally occurring colored compound is found in tiny glands in the seed, leaf, stem, tap root bark, and root of the cotton plant. The adaptive function of the compound facilitates natural insect resistance. The three key steps of refining, bleaching, and deodorization in producing finished oil act to eliminate the gossypol level. Ferric chloride is often used to decolorize cotton seed oil.
Comparison to other vegetable oils
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. It has a relatively high smoke point as a frying medium. Density ranges from . Like other long-chain fatty acid oils, cottonseed oil has a smoke point of about , and 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.
Production
In 2019, world production of cottonseed oil was 4.45 million tonnes, led by China and India with 56% combined of the total.
Economic history
The by-product of cotton processing, cottonseed was considered virtually worthless before the late 19th century. While cotton production expanded throughout the 17th, 18th, and mid-19th centuries, a largely worthless stock of cottonseed grew. Although some of the seed was used for planting, fertilizer, and animal feed, the majority was left to rot or was illegally dumped into rivers.
In the 1820s and 1830s Europe experienced fats and oils shortages due to rapid population expansion during the Industrial Revolution and the after-effects of the British blockade during the Napoleonic Wars. The increased demand for fats and oils, coupled with a decreasing supply caused prices to rise sharply. Consequently, many Europeans could not afford to buy the fats and oils they had used for cooking and for lighting. Many American entrepreneurs tried to take advantage of the increasing European demand for oils and America's increasingly large supply of cottonseed by crushing the seed for oil. But separating the seed hull from the seed meat proved difficult and most of these ventures failed within a few years. This problem was resolved in 1857, when William Fee patented a huller, which effectively separated the tough hulls from the meats of cottonseed. With this new invention, cottonseed oil began to be used for illumination purposes in lamps to supplement increasingly expensive whale oil and lard. But by 1859, this use came to end as the petroleum industry emerged and the American Civil War (and the resulting end of slavery in the United States) disrupted the cotton industry.
Cottonseed oil then began to be used illegally to fortify animal fats and lards. Initially, meat packers secretly added cottonseed oil to the pure fats, but this practice was uncovered in 1884. Armour and Company, an American meatpacking and food processing company, sought to corner the lard market and realized that it had purchased more lard than the existing hog population could have produced. A congressional investigation followed, and legislation was passed that required products fortified with cottonseed oil to be labeled as lard compound." Similarly, cottonseed oil was often blended with olive oil. Once the practice was exposed, many countries put import tariffs on American olive oil and Italy banned the product completely in 1883. Both of these regulatory schemes depressed cottonseed oil sales and exports, once again creating an oversupply of cottonseed oil, which decreased its value.