蓝莓中多酚氧化酶的酶学特性

Enzymatic characteristics of polyphenol oxidase from blueberry

为分析蓝莓中多酚氧化酶的酶学特性,本文对影响蓝莓多酚氧化酶(PPO)的酶活力的主要因素:p H、温度、金属离子、抑制剂及热稳定性进行了研究。结果表明:蓝莓中PPO最适p H为6.5,最适温度为30℃,Ca^(2+)和Mn^(2+)对蓝莓PPO有抑制作用,Cu^(2+)、Mg^(2+)、Zn^(2+)、Fe^(3+)对蓝莓PPO有激活作用。柠檬酸、抗坏血酸、L-半胱氨酸及亚硫酸氢钠能抑制PPO酶活,但柠檬酸抑制效果较差。热稳定性实验结果表明:蓝莓果PPO耐热性较差,高温短时可显著抑制PPO酶活性。

To study the enzymatic characteristics of polyphenol oxidase from blueberry,the main factors that affect the activity of polyphenol oxidase（PPO） from blueberry were studied,including pH,temperature,metal ion,inhibitor and thermal stability. The results showed that the optimum pH of blueberry was 6.5 and the optimum temperature was 30 ℃. Ca^2＋and Mn^2＋ inhibited the blueberry PPO,but Cu^2＋,Mn^2＋,Mg^2＋,Zn^2＋and Fe^3＋ had the activation of blueberry PPO. Citric acid,ascorbic acid,L-cysteine and sodium bisulfite could effectively inhibit PPO activity,and the citric acid inhibition effect was poor. And the thermal stability test showed that blueberry PPO had poor heat resistance,and high temperature could inhibit the activity of PPO.