Ultra Low Gossypol Cottonseed as a Cooking Oil and Dairy Feed
Although cotton is considered first and foremost a fiber crop, it is regulated as a food crop by the Food and Drug Administration because its by-products, including cottonseed oil, have long been used in kitchens, the commercial food industry, cosmetics and medical applications. Recently, long-term research supported by Cotton Incorporated has paved the way for an expanded use of cottonseed as a foodstuff.
History of Cottonseed
Cottonseed has been pressed for its edible oil for more than 100 years. Wesson pressed deodorized cottonseed for cooking oil. And in the early 1900s, Proctor & Gamble used hydrogenated cottonseed oil—crystallized cotton—to make Crisco®, vegetable shortening. It continues to be used as neutral-flavored cooking oil, one with a high smoke point that will not burn or scorch in the pan. While Crisco® has since changed its formula, cottonseed oil continues to be used in a variety of prepared foods. It is shelf stable and has low levels of saturated fats, with no trans-fats or cholesterol and is not partially hydrogenated. These properties have boosted its use as an ingredient in foods, such as cereals, breads and snacks. U.S. consumption is about three pints per capita. Though it has not historically been a direct food source for humans, cottonseed has enjoyed success as a dairy feed supplement. Cotton Incorporated worked with growers to develop prepared cottonseed for the feed market, primarily for cows, which are ruminant animals whose stomachs can digest the seed. The result was “seed as feed.” Sold to dairy farmers in pellet form and blocks of feed supplement, they provided a new line of revenue for cotton growers. But the cottonseed itself has never before been used as a human food source because the seed contains a natural pest deterrent called gossypol, beneficial because it works to keep insects and pests away from the plant, but toxic in high doses to humans and other animals. This was a challenge given cottonseed’s very healthful profile: trans-fat free, gluten free, and 23% protein.
In the 1950s, researchers discovered a gossypol-free cotton strain. Scientists bred the trait into traditional cotton varieties, and studies confirmed that the cottonseed meal from the seed was safe for human consumption. Unfortunately, without the gossypol, the cotton plants became a veritable feast for pests and insects. Consequently, researchers went back to the drawing board and considered bioengineering a plant that could fend off the pests while still producing edible seed. Since the 1990s, Cotton Incorporated has helped fund genetic research at Texas A&M University. Scientists there have successfully silenced the gene that produces gossypol in certain parts of the plant. The result is a new ultra-low gossypol plant that contains gossypol only in the stem and leaf of the plant, while leaving only ultra-low (and digestible) levels of gossypol in the seed. Today, 20 million cotton farmers produce 44 million metric tons of cottonseed—the equivalent of 10 million tons of protein. Essentially, the protein requirements of 500 million people a day could be met by using edible cottonseed. Regulatory approvals will take time, but one estimate suggests the U.S. industry is six to 10 years away from planting a million acres (more than 400,000 hectares) of ultra-low-gossypol biotech cotton. As a means to address hunger in developing nations, the potential for ultra-low gossypol cottonseed is enormous. Cotton Incorporated also sponsors an interdisciplinary cottonseed research project at New Mexico State University. The school began growing glandless cotton (gossypol is produced by tiny glands in the cottonseed) two years ago and has been testing it in field and lab trials, which include agronomic and insect resistance evaluation. NMSU grows and harvests test crops of glandless cotton and then presses the cottonseed for cooking oil for use on campus. And their pilot program involves milling glandless cottonseed down for use as a wheat flour substitute in baked goods such as cookies and cakes. NMSU has also created a potentially lucrative new market for ultra-lowgossypol cottonseed by using ground meal for shrimp feed. The cottonseed is ground into a fine consistency and mixed with algae. As part of NMSU’s aquaculture program, this meal is turned into a pellet and fed to farm-raised shrimp. Shrimp are typically fed meal made from processed fish. But with overfishing being a problem in today’s world, cottonseed provides an alternative to the protein found in fish feed.