交联大豆分离蛋白的制备及流变学性质

Preparation of cross-linked soybean protein isolates and their rheological properties

利用二元酶系(辣根过氧化物酶、葡萄糖氧化酶)和葡萄糖,通过一步法或两步法对大豆分离蛋白进行交联处理。以修饰产物中相对二酪氨酸含量为指标,采用单因素实验确定一步法处理大豆分离蛋白的反应的适宜条件为:葡萄糖添加量1.8%、葡萄糖氧化酶添加量4.0U/g蛋白质、辣根过氧化物酶添加量200U/g蛋白质、反应时间3h。在一步法处理的反应条件下,一步法和二步法处理的大豆分离蛋白相对二酪氨酸含量分别为414和381。与大豆分离蛋白相比,交联蛋白分散液的表观黏度和黏弹性均有显著改变,同时其酸凝胶的胶凝时间缩短、胶凝温度降低。

A binary enzyme system consisting of two glucose were used to cross- link soybean protein dityrosine content of the modified SPIs was used as oxidases （horseradish peroxides and glucose oxidase）and solate （ SPI ） via a one- or two- step treatment. The relative ndex to select suitable glucose, glucose oxidase, horseradish peroxides addition and reaction time by single factor trials for the one-step treatment, which were found to be 1.8% ,4.0U/g,200U/g proteins and 3h, respectively.Under the appropriate reaction conditions, the modified SPIs by one-and two-step treatment had relative dityrosine content about 414 and 381 ,respectively.Compared to the original SPI,the aqueous dispersions of the modified SPIs exhibited higher apparent viscosity, storage and loss modulus.At the same time,one-and two-step treatment resulted in a reduced gelation time and lowered gelation temperature.