Abstract: ：The investigation on the oxidative preparation in vitro of theaflavin by using the polyphenol oxidase(PPO) from Trametes trogii was conducted. Results showed that the optimum reaction temperature for PPO produced by Trametes trogii was ranged from 28℃to 36℃, and the optimum pH value for PPO was 5.2. The PPO showed higher activity and stability during the first 30 minutes when the reaction temperature was constant. 96.2% PPO could be precipitated from the crude enzyme solution when 50% Ammonium sulfate was added to. Added PPO (from Trametes trogii) to two-liquid-phase of catechin reaction system, the TFs was produced 10.19%. Compared with the contrast (PPO from fresh tea leaves), the total quantity of TFs (PPO from Trametes trogii) was lower,but the ratio of TF-3-G was much higher when PPO come from Trametes trogii, and the content of TF-3-G reached 68.1%. It occupied 92.08% of the total ester TFs.

Key words: theaflavins (TFs), polyphenol oxidase(PPO), trametes trogii, enzymatic synthesis