Titre du document / Document title

Unraveling the structure of the black tea thearubigins

Auteur(s) / Author(s)

KUHNERT Nikolai ;

Résumé / Abstract

Thearubigins are the most abundant group of phenolic pigments found in black tea accounting for an estimated 60% of the solids in a typical black tea infusion. Fifty years ago the term thearubigins was first introduced and up to now the chemical nature of the thearubigins remains largely unresolved if not mysterious despite many efforts clarifying their structure. This paper summarizes some of our attempts to clarify and elucidate the chemical nature of the thearubigins, presenting for 15 commercially representative teas data obtained using combustion analysis, IR spectroscopy, NMR spectroscopy, Diffusion NMR spectroscopy, UV-vis spectroscopy, Circular Dichroism spectroscopy and atomic force microscopy, MALDI-TOF-MS and ESI-FT-ICR-MS. The thearubigin fractions from these 15 teas are remarkably similar with respect to their spectroscopic fingerprint. The data obtained are consistent with the thearubigins being structures of not more than 2000 Da with more than 5000 individual chemical entities detected that are susceptible to concentration-driven aggregation in aqueous solution, and that retain the chiral properties of the flavanols and theaflavins. By applying petrolomics-style data interpretation strategies and by developing novel data interpretation strategies a structural model for the thearubigins was developed.

Revue / Journal Title

Archives of biochemistry and biophysics    ISSN  0003-9861   CODEN ABBIA4 

Source / Source

2010, vol. 501, n^o1, pp. 37-51 [15 page(s) (article)]

Langue / Language

Anglais

Editeur / Publisher

Elsevier, Kidlington, ROYAUME-UNI  (1951) (Revue)

Mots-clés d'auteur / Author Keywords

Black tea

;

Spectroscopic techniques

;

Theaflavins

;

Thearubigins

;

Mass spectrometry

;

Data interpretation strategies

;

van Krevelen diagrams

;

Kendrick analysis

;

Localisation / Location

INIST-CNRS, Cote INIST : 2015, 35400019265132.0060