响应面法优化低温豆粕大豆分离蛋白提取工艺

采用响应面分析法(RSM)对低温豆粕大豆分离蛋白(soybean protein isolated,SPI)的碱提工艺进行优化。在单因素实验的基础上,选取了影响SPI提取率的4个关键因素(pH、温度、时间和液料比)进行四因素五水平的中心组合旋转实验设计(CCRD)。通过RSM建立了响应值(SPI提取率)与各影响因素之间的回归方程,并获得了SPI的最优提取条件:pH 8.5,提取温度55℃,提取时间42.8 min,料水比1∶9.7(g/mL),此条件下SPI提取率预测值为37.12%,与实验值(36.69%)的误差为1.16%。将一次碱提后残渣进行二次碱提,二次提取率为10.16%。2次碱提上清液等电点沉淀的蛋白沉淀率分别为84.03%和85.84%。

Optimization of extraction conditions of soybean protein isolated from low temperature soybean meal by response surface methodology

The alkali extraction process of soybean protein isolated(SPI) from low temperature soybean meal was optimized by response surface methoclology(RSM).Based on the single-factor experiments,the four key factors,including pH,temperature,time,and water-material ratio were selected to design the four-factors-five-levels central composite rotatable experiments design(CCRD).The regression equation between response values(SPI extraction rate) and four-factors was established by RSM.Furthermore,the optimized extraction conditions of SPI were determined as pH 8.50,temperature of 55 ℃,time of 42.8 min,and material water ratio of 1∶9.7(g/mL).Under these conditions,37.12% protein extraction ration was predicted.Compared with the actural protein extraction ratio 36.69%,the relative error was 1.16%,it showed that the optimized conditions were feasible.Moreover,the second protein extraction rate of residue was 10.16%.The protein precipitation rates of two-step alkaline extraction solution were 84.03% and 85.84%,respectively.