Abstract:

Special grade sun dried green tea of Yunnan large leaf was used as the experimental subject to examine the changes and correlations of main chemical components during Pu＇er tea processing. The results demonstrated that the main chemical components changed greatly during Pu＇er tea processing. Tea polyphenol decreased by 59.74%, while theaflavin, thearubigin and theabrownin increased. Among them, the increment of theabrownin was the highest. Its content reached 7.19% in made tea. The content of water extract and free amino acid decreased by 23.36% and 57.98%, respectively, after the end of processing. The content of caffeine and tea polysaccharides increased to some degree, and total ash content changed little. According to the correlation analysis and regression analysis using SPSS software, it was demonstrated that a significant negative correlation was found between tea polyphenol and theabrownin, with correlation coefficient －0.993. In addition, significant positive correlations were also found between water extract and tea polyphenol or free amino acid, with correlation coefficients 0.996 and 0.994, respectively and the regression equation was Y1 = 28.845 + 0.283X1 + 1.429X2. Tea polyphenol had a significant correlation with thearubigin or theabrownin, and the regression equation was Y2 = 45.695－1.180x2－3.641x3.

Key words: Pu＇er tea, processing, change of components, correlation