Enzymatic characteristics and thermal stability model of polyphenol oxidase from potato

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.