Polyphenolic content of Vranec wines produced by different vinification conditions

Macedonian Vranec wines were analysed by HPLC coupled with DAD and MS detections and by spectrophotometric methods. ESI-IT MS and MS–MS methods with alternating ionisation polarity were used for identification of the phenolic compounds. Both, nonflavonoids (stilbens, hydroxybenzoic and hydroxycinnamic acids and derivatives) and flavonoids (flavonols, flavan-3-ols and anthocyanins) were detected in the samples. Vranec wines were produced under different fermentation conditions: maceration time of 3, 6 and 10 days, two doses of SO2 (30 and 70 mg l−1) and two yeasts for fermentation, in order to examine their effects on the extraction of phenolic compounds from grapes into the wine.