Kinetic investigations of the sulfite addition on flavanols

This summary follows this made by Hervé Hannin et al. Entitled “French wine sector facing climate change (part. 1) : a national strategy built on a foresight and participatory approach “. The french wine sector has taken a collective approach to the issue of climate change, and has officially submitted its strategy to the minister of agriculture in 2021. This industry policy is the result of multidisciplinary work carried out through the “laccave” project (metaprogramme accaf, inrae) and its prospective study designed to anticipate climate change in the french wine industry (aigrain p. Et al., 2016). French wine professionals decided to structure a strategy to deal with climate change du in particular to the presentation made at the 2016 OIV congress in Brazil.

In the Cognac region in France, Ugni blanc is the most planted grape variety (98% of the 80 500 ha). This vine region is in expansion due to the success of the associated well-known brandy and the need of high grape yield to guarrantee the production of base wine for distillation. About 2 to 3000 ha are newly planted each year and rootstocks are one powerfull tool for vineyard adaptation to soil or climate change. As rootstocks ensure water and mineral nutrient supplies to the scion, it is important to better understand their effect on berry compostionnal parameters such as sugars and nitrogen compounds, which are the main precursors for fermentary aroma metabolites, the latter being quality markers for Cognac after distillation.

Table grapes, being consumed as fresh, raisins, and transformed products are among the most appreciated fruits worldwide. Its popularity is increasing also due to its organoleptic and nutritional qualities that meet the consumers’ interest in healthier foods. Recent data from International Organization of Vine and Wine (OIV) revealed that table grape production has doubled in the last twenty years, and varietal availability has increased thanks to the several breeding programs.
To maintain the socio-economic impact of this sector, new challenges need to be addressed.

Non-saccharomyces yeasts gained an increased interest in winemaking during the last decades, due to their ability to produce relevant amounts of polysaccharides. Moreover, a significant release of glutathione into the wine during fermentation was also observed with these strains, as well as an improvement of color stability and wine aroma profile. Valuable results have been obtained by hanseniaspora spp. concerning the release of polysaccharides and the production of acetic esters, mainly during fermentation.

Grape flavour management in the vineyard requires knowledge of the derivation of individual flavour and aroma characteristics and the effects that different concentrations and interactions between these compounds have on flavour potential.