普洱茶发酵过程中不同外源添加物对氧化酶活性与成分变化的影响

Effects of Different Exogenous Additives on Oxidases Activity and Components During Fermentation of Pu-erh Tea

摘要:

研究了添加不同外源物对云南普洱茶发酵过程中氧化酶活性及成分变化的影响。结果表明,添加不同外源物的发酵普洱茶中抗坏血酸酶活性变化较大:发酵10 d时,酶活性大小依次表现为焦性没食子酸(没食子酸(水(甘氨酸(葡萄糖;发酵20 d时,酶活性大小依次表现为水(没食子酸(葡萄糖(焦性没食子酸(甘氨酸;发酵30 d时,酶活性大小依次表现为焦性没食子酸(葡萄糖(水(甘氨酸(没食子酸。而多酚氧化酶酶活性均呈下降趋势,以一翻样(发酵10 d)最高。发酵前后,添加不同外源物的发酵茶样中茶黄素无明显变化,茶多酚和茶红素含量大幅减少,茶褐素含量大幅增加。这说明,外源添加葡萄糖、没食子酸、焦性没食子酸和甘氨酸对普洱茶发酵过程中酶活性和成分有较大影响,可加速茶褐素的形成。

Abstract:

The effects of different exogenous additives on the activity of oxidases and the change of components during fermentation of Yunnan pu-erh tea were studied.The results suggested that the significant change of ascorbic acid oxidase activity of fermented pu-erh tea was detected with different additives during fermentation process: The activity of ascorbic acid oxidase of pu-erh tea ranked in the order of pyrogallic>gallic acid>water>glycine>glucose when tea samples fermented after 10 days,that after 20 days the order changed to water>gallic acid>glucose>pyrogallic>glycine,that after 30 days in the order of pyrogallic>glucose>water>glycine>gallic acid.The activity of polyphenol oxidase of tea samples appeared a downward trend with different exogenous additives addition during fermentation,and the polyphenol oxidase activity in the first pile-up(ferment for 10 days) sample was the highest.The contents of theaflavins have no significant changes and the content of polyphenols and thearubigins reduced significantly,and the content of theabrownins increased significantly of fermented pu-erh tea samples with different additives.The study indicated that the different exogenous additives such as glucose,gallic acid,pyrogallic and glycine exhibited remarkable effects on the oxidases activity and the components of pu-erh tea during fermentation,and they could accelerate the formation of theabrownins in pu-erh tea.