FLAVONOL GLYCOSIDE CONTENT AND COMPOSITION OF TEA INFUSIONS MADE FROMCOMMERCIALLY AVAILABLE TEAS AND TEA PRODUCTS

The composition and content of flavonol glycosides (FGs) have been mea sured in infusions of a range of black tea and black tea products. Tea contains a mixture of glycosides of quercetin, kaempferol, and myrice tin and the total level of these glycosides, in infusions prepared in a normal domestic manner, for the leaf teas varied from 36.5 to 88.3 m g/L, although greater variation was observed for the tea products, fro m 7.0 to 428.1 mg/L. Altogether seven quercetin, five kaempferol, and two myricetin glycosides were detected; their relative amounts varied significantly in the different samples. The significance of these diff erences in relation to the bioavailability and potential bioactivity o f these compounds is discussed.