大豆肽的超滤分离及其清除自由基活性研究

摘要

Soy protein isolate hydrolysate was separated by ultrafiltration membranes with different relative molecular weight cut-offs. The effects of operation pressure, mass concentration of feed, ultrafiltration time on ultrafiltration membrane flux were studied. Then the scavenging capacities on ·OH and DPPH· of different ultrafiltration fractions were studied. The results showed that the optimal ultrafiltration condi-tions were determined as follows:operation pressure 0. 2 MPa, mass concentration of feed 50 g/L, ultra-filtration time 80 min for ultrafiltration membranes with relative molecular weights of 10, 3, 1 kD, ultra-filtration time 100 min for ultrafiltration membrane with relative molecular weight of 5 kD. The soy pep-tide of relative molecular weight less than 3 kD had higher radical-scavenging rate, and the scavenging rate of ·OH and DPPH· showed some degree of correlationship.%采用不同截留相对分子质量的超滤膜进行超滤分离大豆分离蛋白酶解液，研究超滤过程中操作压力、料液质量浓度、超滤时间对超滤膜通量的影响，确定最佳超滤条件，并测定各超滤级分清除·OH与DPPH·的能力。结果表明：在操作压力0.2 MPa、料液质量浓度50 g/L、通过相对分子质量为10、3、1 kD超滤膜的操作时间80 min、通过相对分子质量为5 kD的超滤膜的操作时间100 min的超滤条件下分离大豆肽，超滤效果较好；相对分子质量小于3 kD的小分子大豆肽具有较高的自由基清除率，且对于·OH与DPPH·的清除率具有较高的一致性。