复合酶水酶法提取大豆蛋白的工艺优化

Optimization of Multi-enzyme Hydrolysis for Soybean Protein Extraction

采用复合酶水酶法提取大豆蛋白。水解酶选用碱性蛋白酶,复合酶采用纤维酶、半纤维酶、果胶酶。得出最优复合酶水酶法提取大豆蛋白工艺条件为料水比1:6(g/mL)、纤维素酶添加量0.64%、半纤维素酶添加量0.56%、酶解pH5、酶解温度37℃条件下水解0.75h后,再利用Alcalase碱性内切蛋白酶,加酶量1.85%、酶解温度50℃、酶解pH9.26、水解3.6h。经过验证实验可知,在最优酶解工艺条件下总蛋白提取率可达到极大值即85.78%。经过复合酶酶解预处理比传统的湿热预处理的总蛋白提取率提高了近10%,其原因经分析是经过复合酶酶解处理的豆粉其细胞结构充分破坏,使得酶的作用位点暴露更有利于蛋白酶的作用,具体的机理分析有待进一步研究。

A two-step enzymatic method was presented for soybean protein extraction by sequential hydrolysis with multiple enzymes （simultaneously added） and alcalase. The multiple-enzyme hydrolysis process was optimized by using mixed design to modeling the effects of cellulase amount, hemicellulase amount, pectin amount and hydrolysis time on total protein extraction efficiency. The optimal hydrolysis conditions for soybean protein extraction were hydrolysis at pH 5, 37 ℃ and a material/ liquid ratio of 1：6 （g/mL） for 0.75 h with 0.64% cellulase and 0.56% hemicellulase and for another 3.6 h at 50 ℃ and pH 9.26 with 1.85% alcalase. Under these conditions, a maximum total protein extraction efficiency of 85.78% was observed. Multipleenzyme hydrolysis caused an increase in total protein extraction efficiency by nearly 10% when compared with traditional heatmoisture treatment. We speculated that the reason for this was due to complete disruption of the soybean cellular structure after multiple-enzyme hydrolysis. However, the detailed mechanisms remain to be clarified.