On the enzymological feature of polyphenol oxidase from tea

Polyphenol oxidase(PPO) was extracted from tea leaves with sodium phosphate buffer(pH5.6) and fractionated with solid ammonium sulfate.Spectrophotometer method was applied in the experiment to study the characters of PPO from tea,such as proper pH,optimum temperature and inhibitors.The results showed that when catechol was used as enzyme substrates,the proper pH was 5.6,the optimum temperature was 50 ℃,ascorbic acid,sodium sulfite,L-cysteine,benzoic acid and cinnamic acid were inhibitors of PPO from tea.Different substrates had different effects on PPO activity.