Structure elucidation of tea thearubigin

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K05421
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38050:Food sciences-related
• Research Institution: Gifu University
• Principal Investigator: YANASE EMIKO 岐阜大学, 応用生物科学部, 教授 (60313912)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: Black tea / catechin / thearubigin / oxidation

Outline of Final Research Achievements

During the processing of black tea, enzymatic oxidation converts tea catechins into a complex mixture of oxidative products, including thearubigins. Ultra-performance liquid chromatography was carried out to analyze the tea extracts collected after each processing stage to clarify the quantitative changes in these compounds during black tea processing. Twenty-three compounds containing the known catechins dimers and flavonol glycosides were identified by liquid chromatography mass spectrometry (LC-MS). In addition, 45 components whose contents increased significantly between the late rolling and late fermentation stages were extracted using principal components analysis by LC-MS.It was estimated from MS/MS analysis that some of them were dimers or trimers with catechin-like units.

Free Research Field

食品科学

Academic Significance and Societal Importance of the Research Achievements

紅茶テアルビジン類は、古くからその存在が明らかになっているにも関わらず、構造情報については推定の域を出ていない現状がある。一方で多くの機能性報告があるのも事実である。カテキン類に限らず、多くの植物中の機能性成分は構造活性相関研究が盛んにおこなわれており、わずかな構造の違いの機能性に及ぼす影響が報告されている。このことからテアルビジン類の化学構造を明らかにすることは重要であり、本研究の成果は新たな知見を付与した点で重要であると考える。また紅茶に限らず多くの植物性食品は収穫後に加工されることが多く、加工時において大きな成分変化が起きていることを示した本研究には社会的な意義があると考える。