Study On Predominant Microorganism And Enzyme And Their Relations To Main Functionality Components During The Fermentation Process Of Pu'er Tea

Pu'er tea is a kind of tea which uses sun dried green tea of Yunnan large leaf species as itsraw material and processed with a unique technology. Microbial fermentation plays a decisiverole in the formation of Pu'er tea quality. Pu'er tea has many health functions, such as weightloss, lipid-lowering, pressure release, and so on. In recent years, Pu'er tea is becoming moreand more popular, the per capita consumption has increased year by year. Therefore, it hasimportant practical significance to research on the relations of microorganism, enzyme andfunctionality components, reveal the tea quality formation mechanism and provide theory anddata support for industrialized fermentation of Pu'er tea.This paper did single strain fermentation using some strains of the predominantmicroflora isolated from Pu'er tea, analyzed the changing regularity of sensory quality andmain chemical components in the fermentation process of Pu'er tea, and then selected fromfive strains, further tested the activity changes of major enzymes from these five strains.The results showed that in the fermentation process of Pu'er tea, the color of tea becameto hepatic from green, the bitter sense of tea soup taperred, the tea soup was red and bright.The contents of tea polyphenol, total amount of catechin and water extract were decreased,while the contents of theabrownin and caffein were increased. This change trend of the mainfunction components was consistent with the natural pile fermentation. The tea had ripe teaquality when fermented20d. The fermentation time is short. It can speed up the fermentationprocess and shorten fermentation period.In monoxenie fermentation process of Pu'er tea, whether the sensory quality andphysicochemical index, mold have a great impact, followed by yeast, while the smallest isbacteria, and almost no effect. Among them, the effect of F-01on the physicochemicalcomposition is the biggest, B-04is the smallest, while the effect of F-12on the quality of Pu'ertea is better.Activity detected results showed that the enzyme activities of polyphenol oxidase, cellulase, pectinase and protease have first increased and then decreased trend in thefermentation process of Pu'er tea. The effects of polyphenol oxidase on each component ofcatechin are very different. The enzyme activities of cellulase, pectinase and protease secretedby F-01and F-12are higher, then the contents of water extracts decrease less.