Cottonseed flakes were extracted with mixtures of nhexane and acetone, with the concentration of acetone varying between 10 and 75%. Adding small amounts of acetone (≤25%) to nhexane significantly increased the extraction of free and total gossypol from cottonseed flakes. Sensory testing detected no difference in the odor of cottonseed meals produced either by extraction with 100% n-hexane or by extraction with a 10:90 (vol/vol) mixture of acetone/hexane. More than 80% of the free gossypol was removed by the 10:90 mixture of acetone/hexane, whereas pure n-hexane extracted about 47% of the free gossypol from cottonseed flakes. A solvent mixture containing 25% acetone removed nearly 90% of the free gossypol that was removable by extraction with pure acetone; the residual meal had only a minimal increase in odor. In contrast, cottonseed meals produced by extraction with pure acetone had a much higher odor intensity. The composition of the cottonseed crude oil was insignificantly affected by the acetone concentration of the extraction solvent. The results indicate that mixtures of acetone and n-hexane can be used as extraction solvents to produce cottonseed crude oil without the concomitant development of odorous meals.Paper no. J11046 in JAOCS 82, 609-612 (August 2005).

A variety of aluminas (acidic, basic, and neutral), silica, and synthetic magnesium silicates were screened to evaluate their potential use as adsorbents for reducing the content of gossypol and related compounds from hexane-based cottonseed miscella. Among the tested adsorbents, one type of silica and two types of magnesium silicate with a relatively high Brunauer-Emmet-Teller (BET) surface area (≥240 m 2 /g) showed a superior adsorption capacity in reducing gossypol from hexane miscella. As a possible regenerating method for the spent adsorbents, washing with acetone was tested. The effect of pH in the washing solvent was also evaluated. Adsorbents that were regenerated by washing with acetone at pH values between 7 and 7.5 performed better than those at pH values between 6.5 and 7. The pH values of washing solvent were adjusted by using a small amount of caustic and 1 M HCl.Paper no. J11047 in JAOCS 82, 905-909 (December 2005).