Allowing cotton to be used in food: this is the project to which Dr. Keerti Rathore has devoted more than half of his professional career. This is not about fibre, used to make fabrics, but about cotton seeds. They are a real protein resource. A wealth not to be overlooked, especially in countries where malnutrition is rampant. Until now, cotton seeds have been unfit for human consumption because of their content of gossypol, a toxic molecule. Recently, the United States Department of Agriculture authorized the marketing of a genetically modified cotton product with a very low gossypol content. So when will cotton find its way to our plates?
Gossypol, a molecule toxic to humans and monogastric animals
Gossypol is a toxin that makes cotton unfit for human consumption. This yellow polyphenolic pigment present throughout the plant is made by the plant to defend itself against pests.
Cotton seeds with low gossypol content
In the 1970s, scientists developed cotton varieties without gossypol. These were then found to be hypersensitive to pests.
It took more than 30 years to discover that the gossypol in the seeds had no effect on pests. Indeed, only the one present in the leaves and stems is used to deter pests.
It is then through the interfering RNA method that a cotton variety with a low gossypol content in the seed was obtained. This genetic modification makes it possible to silence a gene and thus produce a cotton whose gossypol is removed from the seed. However, the concentration of this toxic molecule remains unchanged in leaves, roots and floral organs. This very expensive process is worth it!
The United States Department of Agriculture then authorized the marketing of the genetically modified cotton plant with a very low gossypol content : TAM66274 cotton. This variety meets the World Health Organization’s standards for food consumption. The last step before the first sowing in the field will be approval by the FDA (Food and Drug Administration).
Current use of cotton
Today, cotton seeds are largely underused, mainly for feeding ruminants or transformed into edible oil. For example, the new Milka spread contains a majority of cottonseed oil, up to 20%, and a small amount of palm oil (3.5%) for fat. A composition in transition that is generally better for the environment and health !
The main producing countries are India, followed by China and the United States. Also grown in other Asian and African countries, the future marketing of TAM66274 cotton could then be a new source of income for farmers and a means of combating malnutrition. Indeed, cotton seed has no less than 23% protein, a relatively high rate, compared to white rice, which contains 7% protein, or wheat, 13%. In addition, “If all the cotton currently grown were replaced by an edible variety, we would have enough to cover the daily protein needs of 600 million people” says Kater Hake, vice-president of Cotton Inc, a research association that co-finances Dr. Keerti Rathore’s project.
Cotton in our plates, but in what form?
For the agri-food industry, cotton seed is more similar to oilseeds such as nuts or almonds. It can be enjoyed whole, like a cashew nut for example. But manufacturers are more attracted to its by-products. Their prospects are cotton milk, crackers, cookies, cotton butter or other protein substitutes. Cotton seeds can also be integrated in powder form into energy bars and flours. The industry is also targeting the animal feed market and in particular aquaculture to move towards a more environmentally friendly and cost-effective alternative.
However, it will still be a few years before the land is renewed and the genetic transformation developed is incorporated into commercial cotton varieties.