Identification of the Astringent Taste Compounds in Black Tea Infusions by Combining Instrumental Analysis and Human Bioresponse

✍ Scribed by Scharbert, Susanne; Holzmann, Nadine; Hofmann, Thomas

• Book ID: 120486527
• Publisher: American Chemical Society
• Year: 2004
• Tongue: English
• Weight: 195 KB
• Volume: 52
• Category: Article
• ISSN: 0021-8561
• DOI: 10.1021/jf049802u

✦ Synopsis

Application of taste dilution analyses on freshly prepared black tea infusions revealed neither the high molecular weight thearubigen-like polyphenols nor the catechins and theaflavins, but a series of 14 flavon-3-ol glycosides as the main contributors to the astringent taste perceived upon black tea consumption. Among these glycosides, the apigenin-8-C-[R-L-rhamnopyranosyl-(1f2)-O-β-D-glucopyranoside] was identified for the first time in tea infusions. Depending on the structure, the flavon-3-ol glycosides were found to induce a velvety and mouth-coating sensation at very low threshold concentrations, which were far below those of catechins or theaflavins; for example, the threshold of 0.001 µmol/L found for quercetin-3-O-[R-L-rhamnopyranosyl-(1f6)-O-β-D-glucopyranoside] is 190,000, or 16,000 times below the threshold determined for epigallocatechin gallate or theaflavin, respectively. Moreover, structure/activity considerations revealed that, besides the type of flavon-3-ol aglycon, the type and the sequence of the individual monosaccharides in the glycosidic chain are key drivers for astringency perception of flavon-3-ol glycosides.