Effect of winemaking treatment and wine aging on phenolicudcontent in Vranec wines

摘要

Phenolic compounds and colour stability of redudwines produced from Vranec Vitis vinifera L. grape varietyudwere investigated by means of different maceration timesud(3, 6 and 10 days), two doses of SO2 (30 and 70 mg/LudSO2), two yeasts for fermentation (Vinalco and Levuline),udtemperature of storage and time of aging (3, 6 andud16 months). In general, maceration time influenced theudphenolics extraction from the grapes into the wine. Highestudconcentrations of phenolic components were observed inudthe wines produced with 6 days of maceration, except forudthe flavan-3-ols which were present in highest amounts inudthe wines macerated for 10 days. Higher doses of SO2udincreased the extraction of polyphenols, preventing theudwines from oxidation, while the effect of yeast onudphenolics extraction was not significant. Wine agingudaffected the phenolic content of wines produced withud3 days of maceration and caused intensive decrease ofudanthocyanins during the storage period. Wines aged atudhigher temperature showed lower anthocyanin levels andudless intense coloration. Principal component analysisudrevealed that separation of the wines was performedudaccording to the hue value in correlation with theudmaceration time and time of wine aging.