大豆乳清中蛋白质和异黄酮的超滤分离技术

研究了用超滤技术分离大豆乳清中的蛋白质和异黄酮的工艺条件. 结果表明，大豆乳清在超滤之前要进行预处理以减轻膜污染；通过2因素3水平正交试验，确定了最佳的预处理工艺：按大豆乳清中固形物含量的5%，向其中加入CaCl₂，并在85 ℃下加热15 min，在此条件下，蛋白质的沉淀率为49.8%，异黄酮的保留率为90.4%；通过单因素试验，确定了比较合适的超滤条件：选择切割分子量（MWCO）为10000的聚醚砜膜，超滤压力选择51～68 kPa，超滤温度选择30 ℃～40 ℃.在此条件下，大豆乳清中蛋白质的截留率为83.9%，而异黄酮的截留率为7.6%.

Separation of protein and isoflavone in soybean whey by ultrafiltration

The study on the technical conditions of separating protein and isoflavone in soybean whey by ultrafiltration showed that before ultrafiltration, soybean whey should be pretreated to reduce membrane contamination. The orthogonal experiment of 2 factors and 3 levels indicated that the optimum pretreatment conditions were 5% of CaCl, addition based on the solid substance content in soybean whey, and heating up at 85 degrees C for 15 minutes. Under these conditions, the precipitation rate of whey protein was 49. 8% , while the reservation rate of isoflavone was 90.4%. Single factor experiment showed that the optimum ultrafiltration conditions were poly (ether sulfone) membrane of 10 kDa molecular weight cut-off (MWCO), 51-68 kPa, and 30 degrees C-40 degrees C. Under these conditions, the retention rate of whey protein and isoflavone was 83.9% and 7.6% , respectively.