Effects of Different Exogenous Enzymes and Yeast on Components during Fermentation of Pu-erh Tea

The microbial fermentation plays key role to the development of special quality of Yunnan Pu-erh tea.In this study, unfermented Pu-erh tea was taken as the material and the effects of different enzymes(cellulase, hemicellulase, protease) and yeast additives on the change of components were studied during fermentation of Pu-erh tea.The results suggested that at the 8th of the fermentation stage, the cellulase and the hemicellulase additives increased soluble sugar content to 3.28%,and it's 19.4% higher than the control group.The protease increased free amino acids to 1.52%,and it's 49.0% higher than the control group.The yeast significantly reduced the total polyphenols but did not increase the content of theabrownin,and gallic acid always maintained a low level.It was shown that the effects of different enzymes(cellulase hemicellulase, protease) and yeast additives on the change of components during fermentation of Yunnan pu-erh tea were significantly.