ETHANOL VAPOR DEACTIVATION OF GOSSYPOL IN COTTONSEED MEAL

Most cottonseed cultivars contain gossypol, a polyphenolic antinutriti onal compound. ''Free'' gossypol is a physiologically active form or g ossypol, which is toxic to young- and nonruminant animals. To utilize solvent-extracted cotton-seed meal as a general feed, gossypol must be either removed or deactivated to a minimum level specified for each c lass oi animal. Normally, deactivation is carried out prior to oil ext raction; however, the desired level of deactivation is not always atta ined. A new supplemental method of deactivation has been found by usin g either ethanol or isopropanol vapors on solvent-extracted meal. In a bench-top set-up, ethanol vapor reduced free gossypol from 0.115 to 0 .053%, and a further reduction to 0.026% has been observed with the ad dition of ferrous sulfate. The supplemental deactivation method can, i n most cases, reduce free gossypol to significantly safer levels for f eeding, thus increasing utility, and possibly demand, Tor cottonseed m eal as a general animal feed protein source.