Preparation of Low Free Gossypol and High Available Lysine Cottonseed/Soybean Blends

ABSTRACT Cottonseed/soybean blends (50/50) were ground in an Alpine pin mill with or without previous cooking in a Brady low‐cost extruder. Free gossypol decreased with increasing amount of water added prior to extrusion and number of passes through the extruder. Available lysine increased with decreasing amount of added water but was unaffected by number of passes through the extruder. Type of soybean raw material utilized had no effect on free gossypol. Blends prepared from defatted cottonseed meal, however, had lower free gossypol than those made from cottonseed kernels. A blend similar to full‐fat soy flour but of lower cost was prepared from unextruded 50% defatted cotton‐seed meal/50% extruded soybean flakes, without added water, and ground in the Alpine mill.