Influence of inactive yeasts on polyphenolic composition of Plavina grapes

Abstract

Numerous studies have been dealing with the polyphenolic composition of grapes and wine, mostly due to the influence of individual polyphenols on the sensory properties of wine and their beneficial effect on human health. Due to climate change, which is becoming more frequent, we are increasingly facing the problem of phenolic ripeness of grapes. Therefore, the aim of the study was to determine the influence of inactive yeasts on the ripening of Plavina grapes and phenolic maturity. At the beginning of the veraison, a part of the grapes was treated with inactive yeasts (Lalvigne mature), and as a control variant, Plavina grapes were used, which were not treated. Basic physicochemical analysis and analysis of aromatic and polyphenolic composition were performed in grape samples. A significant difference was observed in the concentrations of petunidin-3-O-glucoside and peonidin-3-O-glucoside as well as kemferol-3-O-rutinoside and procyanidin B1 in the treated grapes while the total acidity was more pronounced in the control treatment. In the aromatic profile, treated grapes had higher content of monoterpenes, while sesquiterpenes were more present in the control treatment. Given the production characteristics of the Plavina variety such as thin skin, susceptibility to disease, compact grapes and large berries with less possibility of dry matter accumulation, which most often produce lighter, weaker colored wines, less rich in polyphenols, the applied technology indicates the possibility of improvement qualitative properties of the Plavina variety and thus of the wine.

Keywords

• plavina grapes
• inactive yeasts
• polyphenols