Study on Polyphenol Oxidase Activities of Tea Cultivars Grown in Sichuan

Crude polyphenol oxidase(PPO) was separately obtained from 5 tea cultivars grown in Sichuan and enzymatic properties were examined to enhance processing qualities of green tea and black tea grown in Sichuan.The results showed that PPO activities increased with the increase of catechol substrate volume when the volume of catechol substrate ranged in 0.3～1.2mL,and decreased when catechol substrate volume was greater than 1.2mL;PPO activities also increased with the increase of temperature when the temperature ranged in 25～45℃,and decreased when the temperature was greater than 45℃;The PPO activities of 5 tea cultivars decreased in varying degree under the condition of 50～90℃ hot water treatment for 20 minutes;PPO could act under alkaline conditions;All the five inhibitors showed some degree of inhibition to PPO activities.