Analysis of caffeine and flavan-3-ol composition in the fresh leaf of Camellia sinesis for predicting the quality of the black tea produced in Central and Southern Africa

A parameter of fresh tea leaf that correlates with black tea quality is highly desired. Twenty good and 20 poor quality tea clones were selected from the breeding programme at the Tea Research Foundation (Central Africa) (TRF(CA)). The flavan-3-ol profile of fresh tea leaves was analysed by capillary electrophoresis while total theaflavin (TF) content was determined in the black tea manufactured from the same leaves for each clone. The above parameters were correlated with total scores and valuation from two tea tasters with regression analysis. The significance of the differences between the 20 good and 20 poor quality tea clones was determined with the Student's t-test. The total TF content of the black tea correlated (r = 0.63, P = 0.0001) well with the value of the tea. Of all the parameters determined in the fresh leaves, the highest correlation was obtained with (-)-epicatechin (EC) (r = 0.65, P = 0.0001). This may facilitate early selection of good quality TRF(CA) clones in the future. (C) 2000 Society of Chemical Industry.