The phenolic pigment composition of black tea liquors—part II: Discriminating origin

Abstract

AbstractThe phenolic constituents of 95 black teas, from nine countries, were analysed by HPLC. The procedure resolved 38 coloured phenolic components which were classified as theaflavins (4), thearubigins (22) and flavonol glycosides (11). One of the thearubigin constituents was unresolved chromatographically, but nevertheless quantified as a hump. The relative levels of these substances for different regions and countries of origin were compared. Statistical analysis of the HPLC results with discriminant analysis or canonical variant analysis and ANOVA, highlighted the characteristic differences in phenolic substance levels which contributed most powerfully to the discrimination between origins. Discriminant analysis revealed a discrimination rule based on phenolic composition which achieved a country of origin classification success of 94%. This type of approach highlights which substances are most important in defining origin in terms of tasters' assessments.