花生乳状液体系中蛋白质的酶解动力学研究

Kinetics of Enzymatic Hydrolysis of Proteins in Peanut Emulsion

摘要:

采用碱性蛋白酶Alcalase 2.4L水解花生乳状液体系中蛋白质，研究了蛋白酶在乳状液体系中的水解特性。结果表明：蛋白质水解度随着初始酶浓度的增加而提高，在酶浓度一定的情况下水解度随着初始底物浓度的提高而降低。蛋白质水解度与乳状液的破乳率存在显著正相关(r=0.983)。在花生乳状液体系中Alcalase 2.4L的水解动力学参数Km=0.0698mol/L，Vmax=3.71×10-4mol/(min·L)。由实验数据推导出蛋白质酶解初级阶段的动力学方程，确定蛋白质水解和乳状液破乳的临界初始底物质量浓度为8.73g/L（加酶量为0.05%）。在酶和底物初始浓度以及反应时间确定的前提下，通过动力学方程可预测破乳过程中蛋白质的水解度及破乳率。

Abstract:

The kinetics of protein hydrolysis catalyzed by alkaline protease Alcalase 2.4L was investigated in the peanut emulsion medium. The results showed that degree of protein hydrolysis was enhanced with the increase of initial enzyme concentration, but it was decreased with the increase of initial substrate concentration at fixed enzyme concentration. There was a good positive relationship between degree of protein hydrolysis and demulsification of emulsion (r=0.983). The apparent Michaelis constant Km was 0.0698mol/L and the maximum velocity Vmax was 3.71×10-4mol/(min·L) in the peanut emulsion. The kinetic equation of peanut protein hydrolyzed by Alcalase 2.4L at initial stage was obtained based on the experimental data. The critical substrate concentration was 8.73g/L (initial enzyme concentration was 0.05%) for hydrolysis of protein and demulsification.