| The aim of this study was to determine the production process of cottonseed peptide from cottonseed meal with microbial degradation of gossypol and protease hydrolysis cottonseed protein techniques.106 strain bacillus that using gossypol as carbon source were isolated from cotton field. After secondary screening, a strain named M57-1 which has better gossypol degradation ability was gained. According to the preliminary identification, it was bacillus. The gossypol degradation rate of M57-1 reach 67.52% and can achieve a better detoxification effect. Optimization conditions of both the strains fermented liquid and solid-state fermentation were decided. M57-1 should be cultured in nutrient broth as the strains fermented liquid for 18 h. While in solid-state fermentation, we used sucrose residue as accessory. The ratio of cottonseed meal with sucrose residue was 4:1, and the quantity of water was 77% of the total weight of cottonseed meal and sucrose residue. 3% of the solid-state fermentation medium, strains fermented liquid was inoculated and cultured at 36℃ for 11 d. For the optimization of fermentation conditions, gossypol degradation can up to 78.96%.This paper studied about the optimization of technical conditions of enzyme hydrolysis to product cottonseed peptide from the gossypol degradative cottonseed meal. The ratio of material to liquor was determined as 1:4 (w/w) and alkaline protease achieve a better effect. Secondary model about the three factors enzyme dose, temperature and enzymolysis time were established by using response surface optimization. Finally, the optimal conditions of the production process of cottonseed protein peptide with alkaline protease hydrolysis techniques was as follow:the ratio of material to liquor was 1:4, dose of enzyme was 1.48%, pH was 8.2 under 51.5℃ for 8 h. In these enzymolysis conditions peptide transform rate can reach 84.52%. This method can significantly increase the production of cottonseed protein peptide and can provide scientific evidence for practice. |
