不同反应条件对勐库大叶种多酚氧化酶合成茶黄素的影响

研究不同因素对勐库大叶种多酚氧化酶催化合成茶黄素的影响,结果表明在p H 4.0、37℃、茶多酚质量浓度为4.5 mg/mL的条件下,勐库大叶种多酚氧化酶催化1.0 h,最有利于茶黄素的合成,其总产量可达(461.12±15.01)μg/mL,转化率为(15.31±0.40)%。勐库大叶种多酚氧化酶对酯型儿茶素催化活性更强,催化合成酯型茶黄素为主,在催化过程中还伴随着表没食子儿茶素和没食子酸的生成,有利于茶黄素的合成积累,这可能与滇红优异品质形成有关。

Effects of Different Conditions on Theaflavins Synthesis by Polyphenol Oxidase of Camellia sinensis var. assamica cv. Mengku

The effects of different factors on the synthesis of theaflavins from tea polyphenols by crude polyphenol oxidase (PPO) from the leaves of Camellia sinensis var. assamica cv. Mengku were analyzed. The results showed that pH 4.0, temperature of 37 ℃, a substrate concentration of 4.5 mg/mL and a reaction time of 1 h were found to be optimum for the synthesis of theaflavins. Under these conditions, the product yield reached (461.12 ± 15.01) μg/mL and the conversion of substrate was (15.31 ± 0.40)%. Additionally, ester theaflavins were the major products of the crude PPO and EGC and GA were also generated during PPO oxidation, which benefited the synthesis and accumulation of theaflavins. These results may be related to the high quality of Dianhong black tea.