Changes in the detailed pigment composition of red wine during maturity and ageing: A comprehensive study Original Research Article

The qualitative and quantitative changes produced, during maturation and ageing, in the pigment composition of a red wine made from Vitis vinifera cv Tempranillo grapes have been studied. In order to determine the detailed composition of the main pigment families involved in the colour changes, a fractionation of the samples has been carried out. One-hundred and twenty-nine different compounds have been identified and their evolutions with wine age have also been established. The data obtained in the analyses of the fractions by high performance liquid chromatography–diode array detection coupled to mass spectrometry (HPLC–DAD–MS) have been used in pigment identification. In order to confirm the identity of some of these compounds, their syntheses have also been carried out. As far as we know, compounds originated by acylation of the monoglucosides of the anthocyanins with lactic acid as well as 3,7-diglucosides of anthocyanins have, among others, been reported here for the first time. The moments of appearance and disappearance of all the detected compounds have also been established as well as the changes in the levels of the different pigment families and subfamilies originated as a consequence of maturation and ageing of the wine in barrels or in bottles. As wine became older, the percentages of anthocyanins decreased slightly, whereas that of the anthocyanin-derived pigments increased and, above all, compounds providing the wine with orange hues (pyranoanthocyanins). In the last sample, they represented 70% of the anthocyanin-derived pigments. On the contrary, the percentage of compounds providing bluish hues to the wine, direct and acetaldehyde-mediated flavanol–anthocyanin condensation products, decreased. This change in the nature of the anthocyanin-derived pigment would explain the colour change observed in the samples, from purple towards orange hues.