马铃薯多酚氧化酶酶学特性及热稳定性模型的研究

Enzymatic characteristics and thermal stability model of polyphenol oxidase from potato

目的:研究马铃薯中多酚氧化酶(polyphenol oxidase,PPO)的部分酶学性质及热稳定性并拟合数学模型预测酶活变化过程。方法:采用紫外可见分光光度计测定马铃薯多酚氧化酶活力,利用Matlab软件拟合二元多项式热稳定性数学模型,SPSS软件对多项式模型回归分析。结果:马铃薯多酚氧化酶的最适pH为5.5,最适反应温度为40℃,最适底物浓度为8.33mmol/L,加工温度、时间与酶活残存率的函数关系为:Z=24.5439+6.1163X+3.4064Y-0.0269X2-0.2361XY-0.0351Y2-0.0002836X3+0.001326X2Y+0.0012XY2,其中R2=0.981,F=100.695,p<0.001。结论:二元三次多项式模型能够较准确的反映并预测马铃薯多酚氧化酶在热加工过程中酶活的变化趋势。

Objective：Evaluated the enzymatic characteristics and thermal stability of polyphenol oxidase（PPO） from potato and fit stability model to predictive the activity of PPO in processing.Methods：Spectrophotometer method was applied to detect the enzyme activity.The thermal stability model of PPO was fitted with Matlab.The regression analysis of polynomial model was analyzed by SPSS.Results.The optimum temperature of polyphenol oxidase was 40℃ and pH was 5.5 ,substrate concentration was 8.33mmol/L.The relationship of technological parameter（time X, temperature Y） and residual activity of PPO was as following ： Z = 24.5439 ＋ 6.1163X ＋ 3.4064Y-0.0269X2-0.2361XY- 0.0351Y2-0.0002836X3 ＋0.001326X2Y ＋0.0012XY2 with R2 =0.981, F = 100.695,p 〈0.001. Conclusion：The model was accurate and had ability of predicting the tendency of enzyme activity changing of PPO during, processing.