Storage deterioration in Central African tea: Changes in chemical composition, sensory characteristics and price evaluation

Levels of thearubigins (TR), the high‐molecular‐weight SII TR fraction, and caffeine increased during storage, while flavanols and soluble solids decreased. The theaflavin (TF) content, except for an initial increase during the brief maturation period, decreased as a linear function of time during a 5 month storage period. The loss of FT was the major factor responsible for the deterioration in quality and the reduction in evaluation of black tea. Commercial consignments of tea lost an average of 3.6 FT units and over 12% in price over a transit/storage period of 6 months. Oxidative enzyme activity was retained in the manufactured tea. Peroxidase activity was regenerated continuously throughout the period of study, but residual polyphenol oxidase activity decreased during the latter stages of storage.