The fate of flavanol–anthocyanin adducts in wines: Study of their putative reaction patterns in the presence of acetaldehyde

Methylmethine bridged flavanol–anthocyanin dimeric adducts (F–A) were synthesised by hemisynthesis using catechin, acetaldehyde and F–A adducts as precursors in order to simulate putative reactions undergoing in red wine. The products obtained, catechin–methylmethine–catechin–malvidin-3-O-glucose and methylmethine-(catechin–malvidin-3-O-glucose)2, were analysed by HPLC–ESI-MS. The fragmentation patterns allowed the confirmation of the structures. These compounds were investigated and found in wine samples (2-year-old table wine and 10-year-old Port wine), thus confirming their formation in vino as a result of flavanol–anthocyanin adducts transformations.