Oenotannins addition in wine: can be the modulation of redox potential predictable?

Red wine ageing is an important step in the red wine evolution and impacts its chemical and sensory characteristics through many chemicals and physico-chemical reactions. The kinetics of these evolutions depend on the wine studied and influence the wine ageing potential. Generally, high quality red wines require a longer period of bottle ageing before consumption¹. The ageing potential is an impor-tant parameter for wine quality and is related to the capacity of a wine to undergo oxidation over time². Phenolic compounds which are ones of the main substrates for oxidation can then potentially modulate ageing potential³.

The AOC Saint-Emilion, one of the most prestigious in Bordeaux, is located on the right bank of the Dordogne upstream from Libourne. The vineyard is planted on Tertiary (Oligocene) and Quaternary geological formations, on which very varied soils have developed. Numerous studies have taken account of this heterogeneity and made it possible to better understand the functioning and viticultural potential of these soils (Duteau et al. 1981, Van Leeuwen, 1991).

Grape by-products (including skins, seeds, stems and vine shoots) are rich in health promoting polyphenols. Their extraction from winery waste and their following purification are of special interest to produce extracts with high added value compounds. Meanwhile, the growing concern over environmental problems associated with economic constraints, require the development of environmentally sustainable extraction technologies. The extraction using semi-continuous subcritical water, as a natural solvent at high temperature and high pressure a technology is promising “green” technology that is environmentally friendly, energy efficient and improve the extraction process in plant tissues.

Obiettivo del progetto è la valutazione dell’influenza climatica e pedologica dell’areale di Montefalco sul vitigno Sagrantino, ponendo particolare attenzione alla componente polifenolica e antocianica. Sono stati quindi messi a confronto, a partire dal 2001 fino al 2008, sei differenti zone tutte situate all’interno dell’areale DOCG Sagrantino di Montefalco; per ciascun vigneto alla vendemmia sono state effettuate analisi sui parametri analitici e sul contenuto polifenolico e antocianico delle uve. Ognuna delle sei zone è inoltre stata caratterizzata dal punto di vista pedoclimatico, valutando l’influenza del clima e della tipologia di suolo sui parametri analitici presi in considerazione.

Muscat of Alexandria is one of the oldest cultivars still existing, globally recognized for its distinctive aroma, and the primary grape variety cultivated in the Greek Island of Lemnos, yielding various white wines with designated origins.