An overview of gossypol and methods of its detoxification in cottonseed meal for non-ruminant feed applications

Cottonseed is a by-product of the cotton crop rich in protein and oil. The products obtained from cottonseed are meal, oil, linters and hulls. The defatted cottonseed meal (CSM) is an important ruminant feed. However, its use in small animals is limited due to the presence of gossypol. Gosssypol is a toxic polyphenolic compound present in the entire cotton plant including its seed. The amount of total gossypol in CSM varies with the species and it ranges between 1.0 to 1.5%. Gossypol causes reproductive diseases and its toxicity level varies with the animals. Also, this substance is a compound of interest for pharmaceutical and medical applications. According to US-Food and Drug Administration, the food and feed products should contain less than 0.045% of free gossypol (FG). Researchers developed various methods, pre-processing (glandless cotton) and post-processing (physical, chemical and biological) for detoxification of gossypol in CSM to obtain FG level within this limit. The detoxified CSM finds application in the feed of dairy, poultry, piggery, aquaculture etc. In this review; chemistry, toxicity, bioactivity, and methods of estimation of gossypol and various strategies undertaken so far to detoxify gossypol in CSM for non-ruminant feed applications have been discussed.