Influence of ageing on changes in polyphenolic compounds in red wines.

The phenolic compounds of wines were measured in two local cultivars -Blaufrankisch and Turan, and three worldwide known varieties: Cabernet Franc, Cabernet Sauvignon, and Merlot. An experiment was carried out in a cool climate wine region in Eger in the vintage of 2009. We have investigated the profile of phenolic contents in new wines and in aged wines. We have compared these wines in two ageing stages. The content of total polyphenols, anthocyanin, leucoantho-cyanin, catechin, the colour intensity and hue were evaluated by a spectrophotometer. Stilbenes (SB) were identified and quantified by HPLC. The content of SB in new wines ranged from 0.44 mg/l to 2.25 mg/l. In aged wines the SB ranged from 0.05 mg/l to 3.12 mg/l. These compounds were influenced significantly by ageing. The positive health effects and the quality attributes of polyphenols would be important to obtain more information about the quality of wines from the nutritional point of view and from the wine processing aspect.