Detection and Partial Characterisation of New Anthocyanin-Derived Pigments in Wine

New anthocyanin-derived red–orange pigments were detected in wine in the course of cross-flow microfiltration experiments. Analysis of the sugar and organic acid released respectively by acid and alkaline hydrolysis showed that the two major products were respectively a glucoside and the corresponding p-coumaroylglucoside. Mass spectrometry indicated molecular masses of 755·5 for the p-coumaroylglucoside and of 447·5 for its aglycone. Therefore, the new pigments are likely to result from condensation reaction between grape anthocyanins (possibly the 3-glucoside and 3-p-coumaroylglucoside of malvidin) and another wine component, which is not a flavanol. This reaction may partici-pate in the mechanism of colour change during ageing of red wines.