Evolution of Flavanols, Anthocyanins, and Their Derivatives during the Aging of Red Wines Elaborated from Grapes Harvested at Different Stages of Ripening

TLDR

The study evaluates how grape ripening stage influences wine color by comparing flavanol and anthocyanin levels in several red wines. Two cultivars were fermented at three ripening stages over two years, then aged 12 months in medium‑high char American oak barrels and 6 months in bottle. Wines from more mature grapes had higher free anthocyanins, but aging reduced these while increasing anthocyanin derivatives that preserve color intensity and add violet hues, demonstrating that later harvests yield more color‑stable, higher‑quality aged wines. Keywords: aging, anthocyanins, color, flavanols, red grapes, red wines, ripening.

Abstract

Several red wines were elaborated to assess the effect of the degree of grape ripening on wine color and on the levels of flavanol and anthocyanin compounds, which are chiefly responsible for the wine color attributes. Two different cultivars and three different degrees of ripening were studied in two consecutive years. The wines were aged for 1 year in American oak barrels of medium-high char followed by 6 months in the bottle. The results showed that the wines made from more mature grapes had generally higher free anthocyanin content, and during aging the decrease of the free anthocyanins and flavanols took place in conjunction with an increase in the levels of the anthocyanin derivatives or "new pigments", which are responsible for maintaining color intensity and adding violet hues in aged wines. From the results obtained, it seems to be clear that the characteristics and composition of grapes harvested later (7−8 days in this region and for these varieties) than the usual time are quite beneficial to obtaining quality aged wines. The phenolic composition of wines made from the last harvested grapes is mainly responsible for the stability of their color, which is extremely important in product acceptance with a significant increase hence of product quality. Keywords: Aging; anthocyanins; color; flavanols; red grapes; red wines; ripening