Formation of new anthocyanin-alkyl/aryl-flavanol pigments in model solutions Original Research Article

The contribution of the aldehyde composition of wine spirit to the colorimetric changes in red Port wine was studied in model solutions by HPLC–diode array detection (DAD) and liquid chromatography (LC)/mass spectrometry (MS). The reaction between anthocyanins, catechin and the several aldehydes was tested with dimers B4 and B2-3′-O-gallate, two of most abundant procyanidins dimers present in young Port wines. Both dimers reacted with oenin (malvidin-3-glycoside, mv3gl) mediated by several aldehydes (such as acetaldehyde, propionaldehyde, isovaleraldehyde, formaldehyde, isobutyraldehyde and benzaldehyde) leading to the formation of the respective alkyl/aryl linked adducts. The structures of mv3gl-alkyl/aryl-dimer (B4 and B2-3′-O-gallate) and mv3gl-alkyl/aryl-cat ((−)-epicatechin and (−)-epicatechin-gallate) were assigned by LC/ESI–MS.