响应面法优化低温豆粕大豆分离蛋白提取工艺

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

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%。

The alkali extraction process of soybean protein isolated （SPI） from low temperature soybean meal was optimized by response surface methoelology （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 rain, 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.