Temperature-based phenology modelling for the grapevine 

Grapevine rootstocks play a pivotal role in influencing scion vigor, yield, and fruit quality, making their selection critical for sustainable vineyard management.

Heat and water stress can accelerate berry sugar accumulation and lead to excessive sugar-to-acid ratios at harvest, producing bland, overly-alcoholic wines. Selecting grapevines for slower sugar accumulation could help maintain wine quality under future, hotter conditions, but these efforts have been stymied by our limited understanding of the traits determining sugar accumulation rates. Here, we measured traits characterizing the structure and anatomy of the sugar transport system – the phloem – in 16 winegrape cultivars and tested for relationships with sugar accumulation rates and cultivar climate classifications.

The French viticultural appellation areas are the result of an empirical, historical and evolutionary selection which, generally, has consecrated a match between natural factors, grape varieties and viti-vinicultural practices. The notion of terroir is the main basis of the Appellation d’Origine Contrôlée in viticulture. It is based on the one hand on privileged natural factors and on the other hand on the know-how of the winegrowers; the whole allowing the production of a wine endowed with an authenticity and a sensory typicity. Wine-growing practices evolve according to progress in viticulture and oenology, while the natural factors of the terroir are much more stable, with the exception of the vintage. They therefore represent a fundamental pillar of the identity of an appellation vineyard.

In some white wines, malolactic fermentation (MLF) is very interesting, and for low pH wines this process is particularly difficult. Although MLF is generally not recommended for sparkling white wine, some winemakers prefer to promote MLF to contribute to organoleptic complexity. Oenococcus oeni is generally the bacterium of choice for MLF.

Analysis of phenolic compounds typically involve spectrophotometric methods as well as liquid chromatography combined with DAD, fluorimetric, or MS detection. However, the complexity of wine phenolic composition generated, in recent years, attention towards other analytical approaches, including those allowing rapid and inexpensive operations. Voltametric AIM Oxidation of white wine phenolics occurs at different stages during winemaking and storage and can have important implications for wine sensory quality. Phenolic compounds, in particular those with a ortho-diphenol moiety, are main target of oxidation in wine. Strategies for the methods are particularly suited for the analysis of oxidizable compounds such as phenolics. The redox-active species can be oxidized and reduced at the electrode, therefore, applications of electrochemistry have been developed both to quantify such species, and to probe wine maturation processes.3 The project on the diversity of Italian wines aims at collecting and analysing large-scale compositional dataset related to Italian white wines.