Abstract: The activity of PPO of lichi hull and the control effect for different inhibitor were studied in this paper. The result showed that the fine substrate consistence was 0.04mol/L, the proper pH was 7.0, the optimum temperature was 40℃ for PPO of lichi hull;citric acid, ascorbic acid,hyposulphite display better inhibition effect on PPO activity. The optimum inhibition condition was 0.05mmol/L citric acid add 0.2mmol/L ascorbic acid add 0.02mmol/L hyposulphite, the PPO residual activity was 14.2%.

Key words: lichi hull, polyphenol oxidase, activity, inhibition