Methylene Chloride Extraction of Gossypol from Cottonseed Products

Abstract

ABSTRACT Methylene chloride was used to reduce the amount of free and total (free plus bound) gossypol in hexane‐defatted meal and the liquidcyclone‐processed (LCP) underflow fraction of glanded cottonseeds from 2.6% and 3.4% to 0.013% and 0.15%, respectively (the accepted level of free gossypol in cottonseed products for food is 0.045%). The cottonseed meals were pretreated one of three ways to rupture the gossypol glands: (a) equilibrated with additional water; (b) suspended in various water‐propylene glycol mixtures; or (c) mixed with an acetic acid‐water‐propylene glycol solution. The gossypol was then readily extracted from the meals with methylene chloride. Low levels of water and acetic acid in propylene glycol aided methylene chloride in the removal of free and total gossypol and did not greatly alter the proximate composition, solubility, and gel electrophoretic properties of proteins; amino acid content; and chemical scores of the treated meals. Success with this process should improve the potential of LCP‐cottonseed by‐product (underflow) as feed or food.