大豆分离蛋白酶法有限水解工艺过程及动力学分析

采用pH-stat法在pH8.0，T=50℃条件下，以Alcalasa酶对大豆分离蛋白进行有限水解处理，探讨了酶与底物摩尔浓度比[E]/[S]和反应时间t对产物水解度及溶解性的影响；研究了相应的有限水解(x＜6.0)过程的动力学特征。实验结果显示，控制主要影响因素为[E]/[S]＜0.4％，pH8.0和T=50℃条件下，在25min内可使产物的水解度x达到约6.0％，并且产物在酸性pH范围的溶解性明显改善。对实验结果的分析显示，水解过程中底物与酶之间的相互作用引起酶的抑制和失活。在此基础上推导出底物存在临界浓度，在实验条件下，其值为96.77mg/ml。

Study on Enzymatic LimitedHydrolysis of Soy Protein Isolate

The enzymatic limited hydrolysis (x ＜6. 0) of soy protein isolate (SPI) was carried out with the pH -stat method under pH8.0, T = 50℃. The effects of the main parameters including [ E ] / [ S ] in mole ratio and reaction time t on the degree of hydrolysis (x) and the solubility were investigated. The results showed that x could be regulated to below 6. 0％ with the mentioned factors[E] / [S] = 0. 4％, T = 50℃ and pH8.0 within about 25min. The solubility of the hydrolysate in acetic pH range got improved obviously. The experiment results showed that the enzyme - substrate intermediate induced the enzyme inhybition and inactivation. A critical[S] would correspond to a [El, which was 96. 77rmg/ml under the experiment condition.