| In order to get high-quality cottonseed oil and cottonseed meal and achieve the purification of gossypol byproduct, the process of extracting free gossypol from cottonseed kernel by organic solvent was studied. On the basis of single factor experiment,the optimal extraction conditions of free gossypol from cottonseed kernel by 70% of acetone were determined by orthogonal experiment. The results showed that the extraction times affected the extraction rate of free gossypol significantly, followed by extraction time, solid-liquid ratio and extraction temperature;the optimal extraction conditions were obtained as follows: extraction temperature 40℃, extraction time 50 min, solid-liquid ratio 1∶15, extraction times three and stirring rate 850 r/min. Under the optimal conditions, the extraction rate of free gossypol reached 89.58%, and the content of free gossypol in cottonseed meal was only 400 mg/kg. The gossypol standard sample and gossypol extracts from cottonseed kernel were heated at 40℃ respectively, the results indicated that free gossypol was easy to transform to other substances under heating. The content of free gossypol in gossypol extracts decreased from 68.19 μg/mL to 25.27 μg/mL when it was heated at 40℃ for 0-8 h, and the loss rate of free gossypol was 62.94%. |
