脉冲强光处理对杨梅多酚氧化酶活性的影响

The Effect of Pulsed Light on the Activity of Polyphenol Oxidase from Bayberry

采用响应面法研究脉冲强光对杨梅中多酚氧化酶(PPO)活性的影响。设定3个影响因素分别为脉冲强度(150～450 mJ/cm2),闪照次数(3～7),酶溶液pH(3.0～7.0)。实验结果表明:各处理因素对酶的活性具有显著性的影响(p<0.05),其中溶液pH值对酶活性的影响最为显著。该回归方程的拟合度高,能够预测不同处理条件对酶的钝化效果。根据回归方程可知,在pH 3.2的条件下,采用450 mJ/cm2闪照7次的脉冲强光处理,可使PPO酶的钝化率达到54.7%。

A response surface was used to establish the effect of pulsed light （PL） on bayberry polyphenol oxidase （PPO） inactivation. Three processing factors setting at the treatments were pulsed energy from 150 mJ/cm^2 to 450 mJ/cm^2, pulsed times from 3 to 7 and pH from 3.0 to 7.0. Result showed that, various processing factors had a significant effect on the PPO activity, with most significant effect of pH. The effect of these parameters on PPO inactivation was well evaluated through a second order model that adequately fitted the experimental data. According to the equation, the activity of PPO dissolved in pH 3.2 buffer decreased by 54.7% after pulsed light treatment of 7 times at 450 mJ/cm^2.