Review of the different methods for the evaluation of the in vitro antioxidant activity of wine and study of in vivo effects.

The aim of this paper is to evaluate the significance of these methods, as well as to correlate the antioxidant activity of wines with their phenolic profile, both in qualitative and quantitative terms. Red wines show higher antioxidant capacities than white ones and the magnitude of these differences depends on the method used. The antioxidant activity of wine can not be mainly ascribed to a particular phenolic compound, instead it is explained by the global interaction of all of them. To evaluate the influence of red wine consumption in the human organism, plasma antioxidant capacity has been frequently used as biomarker, and studies have shown that it increases after wine ingestion. We can conclude that it is necessary to use a battery of methods that provide different and complementary information to properly interpret the results. Phenolic compounds undergo metabolic transformations in the organism which modify their activities. In vivo assays do consider these changes. From the studies performed up to date we can conclude that acute ingestion of wine directly acts on plasma antioxidant capacity due to phenolic compounds and indirectly influences by means of changes on plasmatic concentration of endogenous antioxidants.