酶改性大豆分离蛋白的制备及产品功能性的研究

Preparation and functional properties of enzymatic modified soybean protein isolate

为了改善碱溶酸沉法大豆分离蛋白产品(简称SPI)的功能性,采用有限酶解的方法,从6种蛋白酶中选出中性蛋白酶(Neutrase)作为改性用酶。通过单因素实验,分析了底物浓度,E／S,反应时间对水解度和氮收率的影响,并通过正交实验确定制备酶改性大豆分离蛋白(简称ESPI)的最佳工艺参数为:底物浓度为3％,E／S为1 200 U／g,时间为60 min。得到的ESPI的蛋白含量与SPI相近,但NSI由SPI的90％提高到97％。而且在功能性方面,ESPI也得到了很好的改善。

To improve the functional properties of SPI prepared by the method of alkali-extraction and acid-precipitation , the method of limited enzymolysis was adopted. Neutrase protease, which was selected from 6 kinds of proteases, was as the modification reagent. Through the single factor experiment, the effects of the substrate concentration, E/S and reaction time on DH as well as on the nitrogen recovery were described. And through perpendicular experiment, the optimized conditions of enzymolysis were determined as following: substrate concentration was 3 % , E/S was 1 200 U/g and the reaction time was 60 min.The protein content of SPI modified by enzyme (ESPI) was close to that of SPI prepared by the method of alkali-extraction and acid-precipitation (SPI). But NSI of ESPI, which was up to 97% ,was higher than that of SPI, which was 90% . Meanwhile, many functional properties of the ESPI were greatly improved, especially in the property of emulsification as well as foaming.