草鱼鱼糜漂洗液中蛋白肽的制备及其功能性质的研究

Study on Preparation and Functional Properties of Polypeptides from Wash Liquid of Grass Carp Surimi

以草鱼鱼糜漂洗液回收蛋白为原料,短肽得率和水解度为指标,从5种常用蛋白酶中选出碱性蛋白酶作为酶解回收蛋白的最适酶,通过单因素和响应面优化试验得出最佳酶解条件:酶解温度为52.51℃,酶解pH为9.06,酶添加量为1.42%,酶解时间为60min,酶解底物蛋白浓度为1g/dL。在此条件下回收蛋白的水解度为20.86%,短肽得率为73.5%;比较酶解前后回收蛋白的功能性质,发现酶解后多肽的溶解性、乳化性和起泡能力有所增加,乳化稳定性、泡沫稳定性和持油性较酶解前有所降低。

Proteins recovered from grass carp surimi wash liquid are as raw materials, alkaline protease is identified as the most suitable enzyme for enzymatic hydrolysis of protein among 5 commonly used enzymes based on simultaneous consideration of trichloroacetic acid nitrogen solubility index （TCA-NSI） and degree of hydrolysis （DH）. According to single factor experiment and response surface methodology, the optimal enzyme reaction system is obtained as follows： hydrolysis temperature is 52. 51℃, hydrolysis pH is 9.06, enzyme additive amount is 1.42%, hydrolysis time is 60 rain and substrate concentration is 1 g/dL. Under the optimal hydrolysis conditions, the TCA-NSI and DH are 73.5 % and 20.86 %. The functional properties of protein before and after hydrolysis are compared; the results show that the solubility, emulsifying and foaming of protein have been increased after enzymatic hydrolysis than before. However, the emulsifying stability, oilabsorption capacity and foaming stability are decreased.