转谷氨酰胺酶交联对罗非鱼下脚料酶解蛋白功能特性的影响

Effect of transglutamiuase on functional properties of hydrolyzed protein from Tilapia by-products

采用转谷氨酰胺酶对罗非鱼下脚料胰蛋白酶水解产物(DH5.0%)进行交联改性研究,结果显示:底物浓度10%、加酶量5.0 U/g、温度50℃、pH7.0、反应时间2 h,TG交联产物的乳化性和发泡性较好,分别比交联前提高1.35倍和1.20倍。经Sephacryl S-200凝胶过滤层析证明,TG交联改变了蛋白分子结构,使内部的疏水性氨基酸暴露出来,同时也使蛋白分子之间彼此连接形成空间网络结构,这有助于改善酶解蛋白的乳化性和发泡性。

Hydrolyzed proteins （DH5.0%） were enzymatic-cross-linking modified by transglutaminase in this study. The results showed that a substrate concentration of 10%, a enzyme dosage of 5.0 U/g, temperature 50 ℃, pH7.0, reaction time 2 h, emulsifying ability and foaming ability of TG-polymer were the best, 1.35 and 1.20 times before modification respectively. The molecular weight distribution of TG-polymer was detected by using Sephacryl S-200 gel filtration chromatography. Foaming properties have improved to some extent. The results showed that the protein molecular structure was changed by TG-cross-linking. Internal hydrophobic amino acids were exposed and a network structure was formed between the protein molecules, which helps to improve the emulsifying and foaming properties of the hydrolyzed protein.