Effect of microbial polyphenol oxidase on the color of infused black tea.

Changes of polyphenol oxidase and peroxidase activities and pigment composition of some manufactured black teas (Camellia sinensis L.)

“…A longer reaction time resulted in an increased polymerization forming protein-phenol complexes through combined enzymic reactions (Piffaut and Metche, 1991;Sekiya etaL, 1984;Pierpoint, 1985). Thus, ultrastructural changes undergone during tissue injury can play an indispensable role in transforming ortho diphenolic compounds into quinones, which in turn could favor formation of compounds such as theaflavins and thearubigins of special organoleptic importance (Kato et al, 1987;Spencer et al, 1988;Roberts, 1962).…”