[Biochemical processes at the stage of withering during black tea production].

We determined the molecular weight and some properties of multiple forms of phenol oxidase from tea leaves and four other perennial plants. It was shown that multiple high- and low-molecular forms of phenol oxidase differed in substrate specificity. Low-molecular forms of the enzyme mostly demonstrated hydroxylase activity, while high-molecular forms showed catechol oxidase activity. It was revealed that the withering stage of black tea production is accompanied by the formation of only high-molecular forms of phenol oxidase, which possess catechol oxidase activity crucial for the procurement of oxidative reactions and the quality of the product.