Changes in the quality parameters of clonal black tea due to fermentation time

Flavour index and Group II volatile flavour compounds of clonal black tea progressively decreased while Group I compounds increased during fermentation process. However, theaflavins in made black tea and tasters' evaluation of such tea changed in a quadratic manner with fermentation time. The rate of production of the individual theaflavins varied within a clone and between different clones as fermentation progressed. The results explain the errors obtained when only one quality parameter is used to estimate optimum fermentation time in black tea manufacture.