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In‐vitro studies on the effect of polyphenol oxidase and peroxidase on the formation of polyphenolic black tea constituents
Author(s) -
Finger Andreas
Publication year - 1994
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740660306
Subject(s) - polyphenol oxidase , chemistry , polyphenol , myricetin , peroxidase , high performance liquid chromatography , glycoside , food science , catechin , catechol oxidase , biochemistry , chromatography , flavonoid , enzyme , antioxidant , organic chemistry , kaempferol
Flavanols (catechins and gallocatechins) isolated from green tea leaves ( Camellia sinensis ) (L) O Kuntze) were treated in vitro with polyphenol oxidase, peroxidase and a combination of both. The flavanol levels and those of the products formed were monitored by reversed‐phase high‐performance liquid chromatography (HPLC using spectrophotometric detection at 280 and 380 nm. Flavanols and theaflavins were quantified, whilst integrated peak areas are given for the remaining compounds. After fermentation in the presence of polyphenol oxidase higher levels of theaflavins and resolved thearubigins were obtained, whilst peroxidase produced higher amounts of chromatographically unresolved thearubigins of higher molecular weight, observed as a rise in the HPLC baseline, in the presence of peroxidase a significant decrease in the levels of all flavonol glycosides was observed, whilst in the presence of polyphenol oxidase only myricetin glycoside levels decreased.