Optimization of phenolic compounds extraction from 'Cabernet Sauvignon' cultivar through applying different technological options of maceration and fermentation

Obtaining quality red wines depends both on the composition of the raw material and on the extraction of various components by different techniques applied during the processing of grapes and musts. The studies were performed on 'Cabernet Sauvignon' cultivar cultivated in two different Romanian vineyards, Murfatlar and Copou Iasi. The objective was to assess the possibility of optimization of the phenolic compound profiles of the wines of this cultivar obtained in these two different wine regions, by controlling the skin maceration duration used in the traditional maceration-fermentation for red wines. The length of skin maceration applied was 8 and 16 days, respectively. During the maceration-fermentation process, daily determinations of color intensity, tint, anthocyanins, total polyphenols, and alcoholic content were performed, observing an ascending curve of phenolic compounds accumulation in wine, which peaked after the alcoholic content exceeded 10.0% vol. The phenolic profiles of the wines were also obtained, by determination of the phenolic compounds by HPLC-DAD liquid chromatography. The results obtained for phenolic acids (gallic acid, pyrocatechinic acid, p-benzoic acid, chlorogenic acid, p-coumaric acid and ferulic acid), flavanols (catechin and epicatechin), flavonols (naringin, quercitin), trans-resveratrol and anthocyanin monoglucosides (delfinidine, peoniodine and cyanidine), acylates and coumarilates, revealed significant differences for 'Cabernet Sauvignon' cultivated in different regions, especially for phenolic acids, flavonols and trans-resveratrol. Analyzing the statistical data in view of the influence of the two factors (the vineyard and the duration of the fermentation-maceration process, it was observed that significantly higher values of phenolic compounds were recorded when a longer period of maceration was applied and especially in the Murfatlar vineyard, which is located in a warmer wine region.