A model for predicting black tea quality from the carotenoid and chlorophyll composition of fresh green tea leaf

Abstract

AbstractThe plant pigment (carotenoid and chlorophyll) composition of fresh green leaf of tea for a selection of clones was studied in relation to the quality of black tea produced from processing the same green leaf.The plant pigment composition of the green leaf for nine Kenyan clones was monitored by HPLC at 450 nm. Using discriminant analysis it was shown that clones could be distinguished from one another on the basis of their green leaf plant pigment composition.Using step‐wise multiple regression analysis, a linear relationship was established between the levels of six green leaf plant pigments peak 5 (neochrome), peak 17 and 18 (isomers of lutein and/or lutein epoxide), peak 23 (chlorophyll b type compound), peak 26 (aurochrome) and peak 28 (β‐carotene)) and the quality of the manufactured black tea for the selected clones as assessed by tea tasters' evaluations. The model had an adjusted R‐square value of 0.912 and was significant at P≤ 0.05. The value of the relationship as a means of predicting black tea quality is discussed.