ABSTRACT
The effects of oenological agents, gum arabic, and oenological tannin, added at two different stages in the winemaking of rosé sparkling wines (addition to the base wine and to the sparkling wine after disgorging) on evolution of the phytochemical composition during aging on lees and commercial storage were studied for the first time. The sparkling wines were monitored during 12 months of aging on lees (sur lie, with lees) and commercial storage (bottle storage, without lees), in terms of the polyphenolics, color intensity and antioxidant capacity. It was observed that the stage of the addition of oenological agents influenced the changes in phytochemical polyphenols and antioxidant capacity of sparkling wines. The most notable effects on the polyphenolics were observed in the experiment with the addition of oenological agents to the base wine, which significantly increased the concentrations of trans-resveratrol, gallic and ellagic acids, catechin, quercetin, and myricetin. The addition of oenological agents after the disgorging stage had less influence on the phenolics of the sparkling wines. Caffeic acid, trans-caftaric acid, catechin, tyrosol, and gallic acid were the most abundant polyphenolics in rosé sparkling wines. The winemaking practices evaluated in this study comprise an interesting approach to the improvement and/or maintenance of the polyphenolics, according to winemaking practices, besides providing new knowledge on the evolution of rosé sparkling wines. PRACTICAL APPLICATIONS: Tannins and gum arabic are been described as oenological agents, however, are poorly explored in rosé sparkling wines. Many chemical modifications that occur during the winemaking process, especially due to the second in-bottle fermentation and the yeast contact in the case of sparkling wines, can be determinant of authenticity and quality of sparkling wines. The addition of oenological agents in different stages of the winemaking can provide new insights into the evolution of phytochemical constituents of rosé sparkling wines and draw perspectives for improving technological properties of these wines based on practical experience.