高乳化活性大豆分离蛋白制备工艺

为了制备高乳化活性的大豆分离蛋白(SPI),以豆粕为原始材料,采用微波辅助SPI磷酸化改性,以SPI质量分数、三聚磷酸钠(STP)添加量、微波功率和微波处理时间4个试验条件为影响因子,以乳化活性为响应值,采用中心组合旋转设计法,建立微波辅助SPI磷酸化对乳化活性影响的二次回归模型.结果表明:利用响应面法优化出制备高乳化活性大豆分离蛋白的最适工艺条件为:SPI质量分数10％、STP添加量16％、微波功率480W、微波时间4 min;所得模型拟合度高,试验误差小,可将该模型应用于对微波辅助磷酸化SPI的乳化活性进行分析和预测.在最适工艺条件下,改性后SPI的乳化活性为66.8,乳化稳定性为29.80 min,分别较原粉提高了134.4％和61.6％.

Preparation of Soybean Protein Isolate with High Emulsification Activity

The soybean meal was used as the raw material to prepare soy protein isolate (SPI) with high emulsification activity (EA) by the method of microwave-assisted phosphorylation. A response model was established by the central composite rotatable design, with concentration of SPI, ratio of sodium tripolyphosphate (STP), microwave power, time of reaction as four variables and the emulsification activity (EA) as the evaluation index. Response surface analysis revealed that the optimized conditions of preparation of soybean protein isolate with high EA by microwave-assisted phosphorylation were as follows: concentration of SPI 10%, ratio of STP 16%, microwave power 480W and time of reaction 4min. The response model was valid in analyzing and predicting the extent of EA due to its higher fitting degree and less experimental error. Under the optimal conditions, the EA reached 66.8 and the emulsification stability (ES) reached 29.80min. Compared with the previously unmodified SPI, the EA and the ES were increased by 134.4% and 61.6%, respectively.