复合改性大豆分离蛋白乳液冻融稳定性研究

Study on freeze-thaw stability of composite modified soybean protein isolate emulsion

以大豆分离蛋白为原料,利用超声波协同木瓜蛋白酶对大豆分离蛋白进行改性,并利用高速均质机将改性后的产物制备成O/W型乳状液。以乳化活性指数为指标,在单因素试验基础上通过正交试验确定最佳改性条件。结果表明:最佳改性条件为料液比为7∶100(g/mL)、酶添加量6000 U/g(以大豆分离蛋白质量计)、水解时间1.5 h。在此条件下得到的改性大豆分离蛋白与木瓜蛋白酶改性大豆分离蛋白相比,乳化性提高了4.567%,经过3次冻融循环后,其乳状液分层系数和出油率明显下降。

Using soybean protein isolate as the raw material,ultrasound assisted papain was used to modify soybean protein isolate.The modified product was prepared into an O/W emulsion using highspeed homogenization mechanism.Taking emulsification activity idex as an indicator,the optimal modification conditions were determined by orthogonal experiment based on single factor experiment.The results showed that the optimal modification conditions were material liquid ratio 7:100(g/mL),enzyme addition 6000 U/g(based on the mass of soybean protein isolate),and hydrolysis time 1.5 h.Under these conditions,the emulsibility of the modified soybean protein isolate prepared increased by 4.567%compared with papain modified soybean protein isolate,and the emulsion delamination coefficient and oil yield of its emulsion were significantly decreased after three freeze-thaw cycles.