Influence of the number of CPPU applications on growth, mineral composition and Bunch Stem Necrosis incidence in table grape clusters

Acetaldehyde is a common component of wine. It is already formed during the fermentation being an intermediate in the production of ethanol. Moreover, it can derive from the oxidation of ethanol during the wine production and aging. In wine, concentrations of acetaldehyde range from 30 to 130 mg/L. Acetaldehyde in wine can react with many compounds such as SO2, amino acids and

In red wines, anthocyanins evolve during the wine-making process and ageing. They react with other compounds (such as vinylphenols, acetaldehyde, pyruvic acid…) to form a stable family of compounds called pyranoanthocyanins. Furthermore, the oxidation process can modify the anthocyanic profile of a red wine. It is also interesting to evaluate the occurrence of the different subclasses of pyranoanthocyanins and to characterize their chemical properties. The first objective of this study is to evaluate the occurrence of the different groups of pyranoanthocyanins in an oxidised Merlot wine by a centrifugal partition chromatography strategy. The second goal is to evaluate their relative impact in red wines from Bordeaux region by measuring their concentrations.

In view of increasing drought frequencies due to climate change, enhancing grapevine resilience to water scarcity has become vital for sustainable viticulture.

3-Mercaptohexanol (3MH) is a volatile thiol occurring in several white and red wines, where it can contribute to fruity attributes. Its content is typically high in wines from certain grape varieties, in particular Sauvignon blanc, where it is considered a varietal marker. The strong nucleophilic character of thiols makes 3MH rather unstable during wine storage, due to the presence of several strong electrophilic species. Among these electrophilics, those arising from the oxidation of flavan3-ols such as catechin and epi-catechin have been indicated as critical for 3MH stability. Accordingly, there is a generalized interest towards the ability of vinification practices to reduce 3MH loss during aging through the management of wine flavan-3-ols content.

Knowledge of the reflectance spectrum of grape leaves is important to the identification of grape varieties in images of viticultural regions where several cultivars co-exist.