Enzymatic characteristics of polyphenol oxidase from blueberry

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 p H,temperature,metal ion,inhibitor and thermal stability. The results showed that the optimum p H of blueberry was 6.5 and the optimum temperature was 30 ℃. Ca²⁺and Mn²⁺ inhibited the blueberry PPO,but Cu²⁺,Mn²⁺,Mg²⁺,Zn²⁺and Fe³⁺ 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.