Study on PPO characteristics of M.angusticepes

The object of the study was to analyze the characterization of M.Angusticepes polyphenol oxidase ( PPO) by spectrophotometer method 420nm. The fresh - cut M. Angusticepes was cleaned and cut, smashed and centrifuged at 4℃, 12000r /min. The obtain crude PPO in the supernatant was used to measure the optimal pH, temperature and Kinetic property and inhibition of various chemicals to the enzyme. The results showed that the optimum PPO temperature was 30℃, the optimum pH of PPO was 7.5.The reaction kinetic of enzymatic browning was accordant with Michaelis equation, the Km and Vmax were 0.4769mol /L and 1.901mol /L respectively. Ascorbic acid showed the most effective inhibitory activity, followed by sodium hydrogensulfite, and then citric acid.