Abstract
A model fermentation system has been designed which utilizes pure catechins and partially purified polyphenol oxidase (EC 1.14.18.1 from green tea shoots. HPLC analysis of the products formed during in vitro oxidation has demonstrated a close similarity between this system and in vivo oxidation occurring during factory fermentation. Furthermore, changes in theaflavin and thearubigin levels, revealed by time courses of fermentation, show in vitro and in vivo systems to be qualitatively similar, although the former system produces considerably higher levels of both components. The model fermentation system, therefore, appears to be a suitable experimental system for studying the formation of theaflavin and thearubigin pigments under strictly controlled conditions. In preliminary experiments the theaflavins have been identified on HPLC profiles by enzymic oxidation of the relevant catechin pairs. Similarly, major coloured components other than theaflavins, which are considered to be thearubigins, have been shown to be formed by the oxidation and reaction of two gallocatechins (epigallocatechin and epigallocatechin gallate). The model fermentation system, in conjunction with HPLC as described in this paper, provides a means whereby precise data on theaflavin and thearubigin formation can be obtained and, in the case of the thearubigins, one which could yield additional structural information.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
