Effect of prolonged (150 days) post-fermentative maceration in steel tanks and oak barrels on Cabernet Sauvignon wine quality: mathematical modelization of the phenolic compounds behaviour

Abstract

The aim of this study was to evaluate the effects of the prolonged post-fermentative maceration during the winemaking of Cabernet Sauvignon grapes in oak barrels and steel tanks and apply to this purpose a mathematical modelization to better and easily understand the dynamics and phenomena related to this process. The study focused on the time series of phenolic and volatile compounds in wines during the maceration with solid parts and residual components of the alcoholic fermentation, only for anthocyanins and non-anthocyanic flavonoids two mathematical models were proposed. The results showed that the presence of solid parts during the post-fermentative maceration phase provided a higher content of polyphenols and total flavonoids in both oak barrel and steel tanks. The largest contents of polyphenols and flavonoids were observed in oak barrels trials. Among the anthocyanins in both trials we have assisted to a decreasing trend in delphinidin-3 glucoside, cyanidin-3glucoside, petunidin-3-glucoside and peonidin-3-glucoside, with a more accentuated process for the first two molecules in barrique trial, also acetylated anthocyanins showed a decreasing trend more intense in barrique trial. Finally, the post fermentative maceration did not affect HCTA and flavonols concentrations in wines, but rather it affects their chemical stability through the time. Post-fermentative maceration improved the sensory characteristics in terms of intensity, complexity, and persistence at both olfactory and gustatory level, especially in oak barrel vinification.