Stepwise solvent extraction of low temperature pressed cottonseed cake with hexane and methanol

Hexane was used as a solvent to extract cottonseed oil from low temperature pressed cottonseed cake,and then methanol was used as a solvent to extract gossypol to prepare cottonseed protein.Through single factor experiments and orthogonal experiments,the optimal conditions of extracting oil were as follows:temperature 55℃,granule size 0.75 cm,moisture content of raw material below 9%,ratio of material to liquid 1∶1.2,extraction times 8(once 15 min);the optimal conditions of extracting gossypol were as follows:temperature 60℃,granule size of material 0.75 cm,ratio of material to liquid 1∶1.3,extraction times 6(once 15 min).In these conditions,the finished cottonseed protein with 52.10% protein content(N×6.25,dry basis),0.52% residual oil and 250 mg/kg free gossypol content could be obtained.