Level of single bioactive phenolics in red wine as a function of the oxygen supplied during storage

The influence of three levels of oxygen supply on the phenolic composition of Sangiovese wine was evaluated during 6 months of storage. Oxygenation re duced the total phenolics content and increased the concentration of red po lymeric compounds. Saturation with oxygen every 30 days significantly impro ved the wine colour density as compared to the control. The individual beha viour of phenolic compounds such as (+)catechin, (-) epicatechin, quercetin , caffeic acid, and anthocyanins showed a significant depleting effect of o xygen on wine phenolic composition when wines were oxygenated every month. The supply of oxygen every 60 days limited the oxidation of low molecular w eight phenolic compounds and slightly influenced the wine colour. This conf irmed that oxygenation could improve the evolution of red wines during agei ng, but its control is necessary to reduce detrimental effects upon single bioactive phenolic compounds. (C) 2000 Elsevier Science Ltd. All rights res erved.