国产大麦多酚氧化酶酶学特性的初步研究

以邻苯二酚为底物通过分光光度计法,对国产大麦中多酚氧化酶（PPO）的酶学特性进行了研究。同时建立了 PPO 活性测定方法,确定了大麦 PPO 的米氏常数 Km 为1.96mol/L。结果表明,最适测定条件为酶添加量≤6mL、反应时间为4min,检测波长为415nm;国产大麦 PPO 的最适作用温度为80℃,最适作用 pH 为7.6。PPO 在沸水中处理6min 即可有效抑制其活性。实验中同时考察了柠檬酸、抗坏血酸对大麦 PPO 的抑制作用。

Study on the enzymatic characteristics of polyphenol oxidase in domestic barley

The enzymatic charactics of polyphenol oxidase （PPO） of domestic barley was investigated by spectropholometer using catechol as substrate. And the examination method of the activity of barley PPO was determined, the determinate to Michaelis constant Km of the PPO of barley was 1.96mmol/L. The results showed that the optimum conditions are as followings： the enzyme solution 6mL, reaction for 4min, 415nm absorption wave length, the temperture 80℃ and pH7.6. In the boiling stabilization aspect, treating 6min can effectively inhibit the activity of PPO. Inhibited effect of Crtric Acid, Ascorbic Acid on PPO was also studied.