Phenolics and color components of young Cabernet Sauvignon wines: effect of spontaneous fermentation and bottle storage

In this study, the effects of spontaneous and pure yeast fermentation techniques on anthocyanins and colorless phenolics of Cabernet Sauvignon wines were investigated at the end of alcoholic fermentation and after six months of storage in a bottle. After alcoholic fermentation, 43.55% and 49.58% losses were occurred in monomeric anthocyanin contents of spontaneously and inoculated wines, respectively. Fermentation technique had a significant effect on the concentrations of Mv-3-Glu, Peo-3-Glu and Cy-3-Glu, and their concentrations were found to be significantly higher in spontaneously fermented wines. Regarding colorless phenolic compounds, concentrations of (+) gallic acid and (+) catechin were 19% and 26.8% higher in spontaneously fermented CS wines compared to inoculated wines. After six months of bottle storage, the concentration of anthocyanins showed a significant decrease. The losses in monomeric anthocyanin contents were 52% and 60% in spontaneous and inoculated wines, respectively. Concentrations of Mv-3-Glu, Peo-3-Glu and Del-3-Glu decreased by 48.9–52.6% in spontaneously fermented wines during 6 months of aging, while 56.7–63.2% losses were observed in inoculated wines. Unlike anthocyanins, total phenol contents of wines obtained by both techniques increased notably after six months of storage. 52% and 47.9% increases were observed in the gallic acid concentration of spontaneous and inoculated wines, respectively. However, there were significant decreases in the concentrations of (+) catechin, caffeic acid, syringic acid and p-coumaric acid at the end of storage.