Separation of gossypol from cottonseed

Abstract

There is growing need for edible protein and food due to ever increasing newlinepopulation especially in the developing countries. Agriculture land, on the other newlinehand, is on the decrease as a result of rapid urbanization leading to its diversion to newlineresidential / commercial use. Cottonseed is available in large quantity as a newlinebyproduct of cotton can be an important source of protein as it contains both newlineprotein (20-25%) and oil (17-23%). Presently, hexane is being used commercially newlineto extract oil from steam heated cottonseed at 110oC whereby free gossypol newlinepresent in the seed forms a non toxic complex with the protein. After oil extraction newlinethe cottonseed meal is being utilized in regulated quantities as a supplementary newlineprotein to feed animals only as it is not fit for human consumption. The non-edible newlinecottonseed meal can be converted to edible form if gossypol content in it is newlinebrought within the prescribed safe limit of 450 ppm. newlineThis study is aimed at not only to reduce the gossypol content in the newlinecottonseed meal but also to obtain gossypol in concentrated form for its various newlineestablished uses. Ethanol both in pure and acidified form for extraction due to its newlinebetter dissolving power for gossypol. The study involves a two stage extraction newlineprocess where oil is extracted from the cottonseed using hexane and ethanol for newlinegossypol extraction. Experiments were conducted to determine the optimum process conditions like temperature, particle size and solvent to solid ratio (SR). It was found that at 45 degree C maximum extraction of oil occurred for SR:15 for an average particle size (PS) of 0.6 mm. Hexane was used for oil extraction to get defatted meal. In the second stage ethanol (both pure as well acidified) was used to extract newlinegossypol from the defatted meal to the maximum extent. The data obtained indicate that 62% gossypol could be extracted using pure ethanol whereas ethanol acidified with 0.5M Tartaric Acid could extract up to 92.6 % gossypol at 70C, SR:15.