ANTHOCYANIN MOLECULAR-INTERACTIONS - THE FIRST STEP IN THE FORMATION OF NEW PIGMENTS DURING WINE AGING

The changes in red wine colour on aging are still a challenge. From re cent work involving model experiments, it has been concluded that high quality red wine storage conditions (long period of time, permanent c ontact with wood, low pH values, low temperature and aqueous environme nt), are all in favour of good molecular associations between the wine anthocyanins and the aromatic planar colourless molecules present in such a medium. In this article, factors which affect anthocyanin non-c ovalent interactions will be reviewed. They include pigment and copigm ent concentrations and structures, pH, solvent and temperature. The co mplex of a pigment with one of its copigments may be the starting poin t of a covalent linkage between the molecules. This could explain chan ges in colour and in anthocyanin reactivity observed during the aging of red wines, for instance.