Extraction of low temperature pressed cottonseed cake with 95% ethanol

Ethanol with the concentration of 95% was used as a solvent to extract the residual oil and free gossypol in the low temperature pressed cottonseed cake.The effects on the residual oil and free gossypol content in the meal of influence factors,such as granular size,raw materials moisture,extraction temperature,extraction time and ratio of solid to liquid were researched.By orthogonal experiments,the optimal conditions were obtained as follows:granular size 7.5 mm,material moisture less than 9%,extraction temperature 78℃,extraction 12 times(each 15 min),ratio of solid to liquid 1∶3.Under these conditions,the residual oil,the free gossypol content and the protein content in the extracted cottonseed meal were 0.91%,0.012 9% and 51.81%(N × 6.25,dry basis),respectively.