响应面法优化玉米蛋白粉酶解工艺及其动力学研究

Study on enzymolysis process optimization of corn gluten meal by response surface methodology and its enzymatic hydrolysis kinetic

本文采用中性蛋白酶对玉米蛋白粉进行酶解,以氮溶指数(NSI,%)作为筛选指标,在单因素试验的基础上,采用响应面法对影响酶解效果的三个主要因素(底物浓度、酶解时间及加酶量)进行优化确定了最佳酶解条件,之后对玉米蛋白的酶解动力学进行了研究。结果发现中性蛋白酶最佳的酶解条件是:底物浓度为6.85%,酶解时间为3.15 h,加酶量为121.40 mg/g,通过验证试验测得该条件下氮溶指数达63.84%±0.30%,与理论值仅差0.57%。酶解动力学试验结果显示,在不同的底物浓度条件下,酶解速率的变化规律符合米氏方程的特征。采用双倒数作图法计算出Km=36.94 g/L,Vmax=11.66 g/(L·h),得米氏方程式为V=11.66[S]/(36.94+[S]),R2=0.9907,方程极显著,可很好的模拟玉米蛋白酶解动力学过程。该研究可以为开发玉米蛋白深加工产品提供借鉴,有利于提高玉米资源利用率。

The neutral protease was used to hydrolyze corn gluten meal in this study.On the basis of single factor experiment,the optimal enzymolysis condition,including three main influence factors:substrate concentration,enzymolysis time and enzyme dosage,was determined then by response surface methodology with nitrogen solubility index as the optimization index.And after that the enzymolysis kinetic of corn gluten was analyzed.The results showed that the optimal enzymatic conditions of neutral protease were:substrate concentration 6.85%,enzymolysis time 3.15 h,enzyme amount 121.40 mg/g.Under this condition the nitrogen solubility index was up to 63.84%±0.30%by verification tests,which only had a 0.57%difference with the theoretical value.It was found that in the enzymolysis kinetics tests the enzymolysis rate change accorded with the characteristics of Michaelis Equation under different substrate concentrations.The Km and Vmax were calculated by the method of double reciprocal drawing which were 36.94g/L and 11.66g/(L·h)separately,and the Michaelis Equation is V=11.66[S]/(36.94+[S]),R2=0.9907.The equation was very significant which could be used to simulate the enzymolysis kinetic process of corn gluten.This research could provide a reference for deep processing products of corn protein and improve the utilization rate of corn resources.