Study of the phenolic characteristics of wines from the indigenous grape varieties Feteasca Neagră and Rara Neagră

Abstract

Proanthocyanidins, phenolic compounds found in grapes and wines, are oligomers and polymers of flavan-3-ols that play a crucial role in defining the sensory properties of red wines. These compounds contribute to the structure and intensity of color, influence astringency, and enhance aromatic balance, significantly impacting the overall quality of the final product. This research focused on analyzing the phenolic profile of the indigenous grape varieties Feteasca Neagră and Rara Neagră, with particular attention to the procyanidin content and its impact on wine quality. The wines studied were produced in the micro-winery Laboratory of the Oenology Department at the Technical University of Moldova, using different winemaking techniques and grapes sourced from various viticultural regions of the Republic of Moldova. The phenolic composition analysis was conducted using spectrophotometric methods to determine color indices and anthocyanin content, the Foling-Ciocalteu method to assess the total phenolic compounds, and the Bate-Smith method for proanthocyanidin determination. All analyses followed the standards established by the technical regulation HG 708/2011 on wine analysis methods. The results indicated that although wines produced from the same grape variety but grown in different regions exhibit similar physicochemical properties, geographical factors significantly influence organoleptic characteristics. Furthermore, it was observed that Rara Neagră has a lower content of phenolic compounds compared to Feteasca Neagră, which explains the lower color intensity of wines obtained from this variety. The study highlights the value of indigenous Moldovan grape varieties and their contribution to the production of high-quality wines, demonstrating the viticultural potential of the Republic of Moldova.