Crown procyanidin quantification in red wines, rosé wines and Port wines
Condensed grape tannins play a major role in the organoleptic properties and quality of red wine. Recently, a new sub-family of macrocyclic condensed tannins has been identified in red wine and named “crown tannins”. Indeed, the first compound of the family identified and characterised by NMR was the crown procyanidin tetramer which is composed of a macrocyclic structure composed of four (-)-epicatechins link together by B-type interflavanoid linkage in the following an alternative sequences of C4-C8 and C4-C6 linkage. The 3D structure of this unusual crown procyanidin family reveals a central cavity in the molecule . Moreover, this crown procyanidin tetramer has a very specific physicochemical characteristics and properties compared with non-cyclic condensed tannins . Apart from the procyanidin tetramer, many other crown tannins have been detected by UPLC-UV-QTof, such as galloylated tetramers and pentamers. Moreover, recent study showed that these molecules are specifically located in grapes skin and their concentration in red wine depends of the grape varieties.
Thus following or previous work regarding the validation of a quantification method by UPLC-UV-QTof, the evolution kinetics of crown procyanidins family (tetramer, galloylated tetramer and pentamer) during wine aging in bottles over multiple vintages has been investigated. This evolution kinetic has been investigated in various wine matrices, such as red wine, rosé wine and port wine, in order to gain a better understanding of their evolution and impact in the various colloidal matrices. Moreover, this evolution kinetics has been compared with non-cyclic condensed tannins.
1) Zeng, L.et al. (2019) Crown Procyanidin Tetramer: A Procyanidin with an Unusual Cyclic Skeleton with a Potent Protective Effect against Amyloid-β-Induced Toxicity. Molecules, 24: 1915, DOI 10.3390/molecules24101915
Issue: ICGWS 2023
1 University Bordeaux, Bordeaux INP, Bordeaux Sciences Agro, INRAE, UMR 1366, OENO, ISVV F‐33140 Villenave d’Ornon, France