冷榨核桃粕液态发酵制备核桃多肽

摘要

探讨以冷榨核桃粕为主要原料，采用纳豆芽孢杆菌进行液态发酵制备核桃多肽的方法。分析发酵时间、底物质量浓度、起始pH值、接种量及发酵温度对核桃多肽产量和水解度的影响，并通过单因素试验和Box-Behnken响应面分析法对工艺参数进行优化，得到的最优工艺参数为：发酵时间84 h、底物质量浓度8 g/100 mL、起始pH 8.0、接种量11%、发酵温度33℃。此发酵条件下核桃多肽质量浓度和水解度均达到最大值，分别为2.58 mg/mL和37.5%。%Walnut meal, a by-product left after pressing walnuts for oil, contains rich protein and its nutritional value is high. Polypeptide production from cold-pressed walnut meal by liquid-state fermentation ofBacillus subtilsnatto was investigated in this study. The effects of fermentation time, feed concentration, initial pH, inoculum amount, and fermentation temperature on the content of polypeptide and the degree of hydrolysis (DH) were studied, and these fermentation parameters were optimized by single-factor experiments and Box-Behnken response surface methodology. Results showed that the optimum fermentation parameters were determined as follows: fermentation time, 84 h; feed concentration, 8 g/100 mL; initial pH value, 8.0; inoculum amount, 11% and fermentation temperature, 33℃. The maximum content of polypeptide and DH of 2.58 mg/mL and 37.5%, respectively were simultaneously obtained under these optimized conditions.