Impacts of flushing and fermentation times on the quality of black tea

Abstract

Flushing and fermentation times are the two main parameters determining the quality of black tea. In this research, the effects of different flushing and fermentation times were studied on the quality of black tea in two clones, 100 and natural Chinese hybrid. Analysis of variance showed there were the significant differences between the clone types, flushing and fermentation times for theaflavin, thearubigin, total color, brightness, tannin and caffeine. Correlation coefficients between all studied traits, except thearubigin and brightness, caffeine and brightness, and total colour and theaflavin/thearubigin ratio, were significant at 1% probability. Regression analysis indicated there was a significant linear regression between fermentation time and brightness, tannin, and theaflavin/thearubigin ratio. Also, multiple regression analysis for brightness and total colour indicated that more than 70% of the variation in brightness was explained by theaflavin, caffeine and theaflavin/thearubigin ratio, and more than 68% of the variation in total colour was because of caffeine and theaflavin/thearubigin ratio.