固定化酶膜催化茶多酚形成茶黄素反应条件优选

用SAS统计软件中的响应面分析法探讨了固定化多酚氧化酶酶膜催化儿茶素生产茶黄素的最佳反应条件,确定了酶膜法生产高纯度茶黄素的五个重要因素及最佳组合。五个因素包括反应时间、酶与底物之比、通气量、底物浓度和pH值。最佳反应条件为：反应时间49βmin、酶与底物之比为1:128.7、通气量为23.81L/min 、底物浓度5.95βmg/ml和pH值4.3。该条件下产物茶黄素浓度的理论值为0.766βmg/ml,实测值为0.754±0.017βmg/ml,表明优化模型合理,条件筛选结果准确。

Selection of Optimum Conditions for Theaflavin Transformation from Tea Polyphenol through Immobilized Enzyme Membrane

Immobilized polyphenol oxidases (IPPO) was applied for the synthesis of theaflavins using tea catechins as substrates. A Response Surface Methodological (RSM) study was conducted using a five-level, five-variable, central composite rotation design (CCRD) to select the optimum catalysis conditions for theaflavin transformation from tea polyphenol through immobilized enzyme membrane. Five important variables were considered, namely, incubation duration, enzyme/substrate ratio (E/S, Activity Units/ml-AU/ml), aeration volume, concentration of tea polyphenols, and the pH value of the reaction system. The highest theaflavins concentration of 0.766 mg/ml was predicted under the conditions as with 49 min for the incubation duration, 128.7 for E/S ratio, 23.81 ml/min ventilation for air volume, 5.95 mg/ml for catechins concentration, and pH 4.3. The measured theaflavins concentration was 0.754±0.017 mg/ml under the same condition, which suggested that the prediction model was practical and the selected conditions were reasonable.