Exploring diversity of grapevine responses to Flavescence dorée infection

Acidity adjustments are key to microbial control, sensory quality and wine longevity. Acidification with cation exchange resins -in acid cycle- offers the possibility to reduce the pH by exchanging wine cations, such as potassium (K+), for hydrogen ions (H+). During the exchange process, the removal of potassium and calcium ions contributes to limiting the formation of tartrate salts, thus offering an alternative solution to conventional methods for tartrate stability. Moreover, the reduction of wine pH and the removal of metals catalyzers (e.g. iron) could positively impact the wine’s oxidative stability. Therefore, the aims of this work were (a) to optimize the ion exchange process by testing different volumes and concentrations of sulfuric acid (H2SO4) during the acid cycle, (b) evaluate the effects of the ion exchange process on the formation of tartrate salts, and (c) analyze the oxidative stability of the treated wines.

Between 2002 and 2004 we studied the behaviour of two red grape varieties – Merlot and Cabernet Sauvignon – within the scope of an experimental protocol encompassing 14 plots, 7 of which had not been cultivated, situated in geographically distant locations representing different terroirs of Castilla-La Mancha.

Climate projections for the future suggest favourable conditions for some wine producing regions, but challenging conditions for others. For instance, temperature increases are likely to shift grapevine phenology, ripening and harvest dates, and potentially affect grape quality and yield.

La qualité des vins dépend de différents facteurs et procédés, notamment de la nature des terrains viticoles. Dans ce travail, nous avons cherché à établir les liens entre descripteurs pédologiques des parcelles et descripteurs sensoriels des vins. Sur la base de Classifications Ascendantes Hiérarchiques (CAH) et d’Analyses en Composante Principale (ACP), il a été possible d’établir des liens entre la nature des parcelles (sableuse, argileuse, sablo-graveuleuse) et certains descripteurs sensoriels des vins (chaleur, astringence, fruit noir) et plus globalement avec le type de vins élaborés.

The phenolic compounds of red wines represent a source of numerous benefits for human health, which is why they are a constant subject of scientific research. Winemaking in Serbia has a growing economic significance, with particularly autochthonous varieties included [1]. This research identifies and quantifies phenolic compounds of Serbian red varietal wines of Prokupac and Black Tamjanika varieties. Quantification of the level of phenolics has been conducted, including molecular tannins [(+)-catechin, (-)-epicatechin, procyanidin dimers B1, B2, B3, B4], molecular anthocyanins, and the mean degree of polymerization of tannins by HPLC by UV detection, total antioxidant capacity via spectrophotometric methods and chromatic characteristics via CIELAB.