Degradation of oligomeric procyanidins and anthocyanins in a Tinta Roriz red wine during maturation

S u m m a r y : A young red Tinta Roriz wine was stored for three months at different temperatures (12, 22, 32, 42 °C) under anaerobic conditions and after adjusting the SOZ to 0, 50, 100 mg/1 . Changes in wine phenolic composition, especially the procyanidins and anthocyanins were measured using HPLC reverse phase . Dimeric (B1, B2, B3, B4), galloylated dimeric (B1-3-O-gallate, B2-3 O-gallate, B2-3'-O-gallate) and trimeric procyanidins (C1, T2) were quantified during the maturation of the red wine, and their losses were found to be logarithmic with time . Temperature exerts a marked influence on the progressive degradation of procyanidins, while the presence of SOZ slows down the degradation. Comparing their activation energies the dimer procyanidins B1, B2 and B3 appear to be more stable to degradation while trimer T2 and B2-3-O-gallate are most reactive . Concerning the anthocyanins, the acylated monoglucosides degrade faster than the other monoglucosides and the p-coumaric acid acylated pigments disappear faster than the acetic acid acylated pigments.