FLAVANOL COMPOSITION AND CAFFEINE CONTENT OF GREEN LEAF AS QUALITY POTENTIAL INDICATORS OF KENYAN BLACK TEAS

The flavanol composition and caffeine content of green tea leaf, black tea quality parameters of theaflavins, thearubigins, liquor brightnes s and total colour varied more among clones than with time of the year . In green leaf, either (-)epicatechin gallate or (-)epigallocatechin gallate was the dominant flavanol present. Regression analysis of tast ers' preferences for black teas against green leaf chemical components showed positive and significant correlations for (-)epicatechin galla te (r = 0.498, P less than or equal to 0.05 for taster A; r = 0.665, P less than or equal to 0.01 for taster B, and r = 0.678, P less than o r equal to 0.01 for both tasters' overall ranking), (-)epigallocatechi n gallate (r = 0.513, P less than or equal to 0.05 for taster B; r = 0 .532, P less than or equal to 0.05 for both tasters' overall ranking a nd caffeine (r = 0.523, P less than or equal to 0.05 for taster A; r = 0.657, P less than or equal to 0.01 for taster B; and r = 0.686, P le ss than or equal to 0.01 for both tasters' overall ranking). Similar r egressions against black tea theaflavins, thearubigin content, liquor brightness and total colour were not significant. The results suggest that the green leaf chemical components, (-)epicatechin gallate, (-)ep igallocatechin gallate and caffeine could be used as quality potential indicators during clonal selection and propagation.