Changes in theaflavin composition and astringency during black tea fermentation

Both theaflavins and sensory evaluations vary in a quadratic manner with fermentation duration in the process of black tea manufacture. The rate of formation of total (Flavognost) theaflavins varies with clones, and within a clone the individual theaflavins form at different rates with resultant changes in the theaflavin ratios as fermentation progresses. The astringency of black tea also varies with composition and total amounts of the theaflavins, as individual theaflavins have different astringencies. The measurement of total theaflavins may therefore not correctly predict total astringency and hence value of tea.