Abstract:

In order to explore the mechanism for quality improvement of Pu＇er tea, the change of enzymes including cellulase, pectinase, amylase, polyphenol oxidase (PPO), glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) was investigated during different stages of pile-fermentation process of Pu＇er tea. During pile-fermentation process, cellulase and amylase exhibited a similar change trend that was a gradual increase from sun-dried green tea (S0) to 2nd-turned sample (S2), reaching a maximum value, and a subsequent decrease in 3rd-turned sample (S3), which maintained a higher enzyme activity than S0, although the decrease; pectinase exhibited a rapid increase trend from S0 to S1, and a following decline from S1 to S3. In addition, an increase from S0 to S2 and a subsequent reduction from S2 to S3 for the change trend of PPO, GSH-PX and SOD were observed. These investigations also suggested that pile-fermentation degree could provide a significant effect on activities of hydrolases and oxidases. Therefore, proper pile-fermentation process will be of benefit to the improvement of quality and functions of Pu＇er tea.

Key words: Pu＇er tea, pile-fermentation, microorganism, hydrolase, oxidase