Optimization of theaflavin biosynthesis from tea polyphenols using an immobilized enzyme system and response surface methodology.

Theaflavins were synthesized from tea polyphenols extracted from green tea using an immobilized polyphenol oxidase system. To optimize the production of theaflavins, response surface methodology was applied to determine the effects of five critical variables and their mutual interactions on theaflavin biosynthesis at five levels. A total of 52 individual experiments were performed and a statistical model predicted that the highest theaflavin concentration was 0.766 mg ml(-1) at optimized conditions. Using these optimal parameters under experimental conditions in three independent replicates, the average value of the biosynthesized theaflavin concentration reached 0.75 +/- 0.017 mg ml(-1) and matched the value predicted by the model.