Chain-breaking and oxygen scavenging properties of wine as affected by some technological procedures

Antioxidative activity of wines may be reduced or increased by certain technological treatment processes used in winemaking. Effects of SO 2 addition, ageing and concentration of must at high temp. on total polyphenol content, oxygen scavenging ability and chain-breaking activity were investigated in a red wine (Montepulciano d'Abruzzo), a white wine (Trebbiano d'Abruzzo) and a model wine produced using the normal procedure for a typical cooked wine (Marsala-type wine) in S. Italy. SO 2 addition increased oxygen scavenging ability in commercial and model wine samples investigated; chain-breaking activity of wines was not affected. Antioxidative activities of phenols in white and red wine samples were similar despite the lower phenol concn. determined in white wine. A decrease in antioxidative activities of wines was associated with progressive polymerization of phenols during ageing; development of nonenzymic browning reactions during must heating increased antioxidative and chain-breaking activity in wines. It is concluded that technological procedures used in winemaking can cause significant changes in antioxidative activity of wines; with certain treatments, these changes may be positive.