Physicochemical analysis of theaflavins in black tea

2015 Fiscal Year Final Research Report

• Project/Area Number: 25450174
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Food science
• Research Institution: Nippon Veterinary and Life Science University
• Principal Investigator: Nakayama Tsutomu 日本獣医生命科学大学, 応用生命科学部, 教授 (50150199)
• Co-Investigator(Kenkyū-buntansha): ISHII Takeshi 神戸学院大学, 栄養学部, 准教授 (50448700) ; NARAI Asako 日本獣医生命科学大学, 応用生命科学部, 講師 (00339475)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: テアフラビン類 / カテキン類 / HPLC / クーロアレイ検出器 / 過酸化水素 / 酸化還元電位 / 電気化学検出器

Outline of Final Research Achievements

A novel method to evaluate the redox properties of tea polyphenols such as catechins and theaflavins by HPLC-coulometric-array analysis was established. The quantity of electricity (C) on the vertical axis and the electric potential (V), adjusted with the associated palladium reference electrode, on the horizontal axis were plotted to provide “quantity versus potential (QP) plot”. The patterns of the plots correspond to the derivative of a hydrodynamic voltammogram or a current-voltage curve, with the electric potentials of the peaks in the QP plot corresponding to the half-wave potentials in the current-voltage curve. It was confirmed that catechins and theaflavins are oxidized depending on the electric potentials of their partial structures, and that all compounds showing a peak at 0 mV in the QP plots produce hydrogen peroxide during the autoxidation process.

Free Research Field

食品科学