The influence of different fertiliser applications and canopy management practices on the potassium content and pH of juice and wine of Vitis vinifera L. cvs. Cabernet-Sauvignon and Cabernet franc

Balsamic vinegars of Modena (Italy), namely Aceto Balsamico di Modena PGI (AB PGI) and Aceto Balsamico Tradizionale di Modena PDO (ABT PDO) are among the most important geographical indication products for Italy. ABT PDO, despite its very limited production, is recognized as one of the most representative Italian artisan gastronomic products, and it is known and commercialized all around the world. The economic value of ABT PDO (“affinato” and “extra-vecchio” types, depending on the aging), prepared following a traditional way and aged for many years in a set of barrels (transferring a certain amount of vinegar from one cask to another in a decreasing “topping up” procedure) is great, when compared to AB industrially prepared with caramel. AB PGI is certainly the most widespread industrial-type vinegar in the world, deriving from low-temperature condensed grape must (or cooked must) mixed with wine vinegar, obtaining balsamic vinegars with a caramel-like taste. Depending on its economic value, ABT PDO is often object of fraud, requiring to fight counterfeit products and imitations.

The objective of the present work is to assess yeast effects on the development of wine varietal aroma throughout aging and on wine longevity.

Three independent experiments were carried out; two fermenting semi-synthetic musts fortified with polyphenols and aroma precursors extracted from Tempranillo (1) or Albariño (2) grapes and with synthetic precursors of polyfunctional mercaptans (PFMs), and a third in which a must, mixture of 6 different grape varieties was used. In all cases, fermentations were carried out by different Saccharomyces cerevisiae strains and one S. kudriavzevii, and the obtained wines were further submitted to anoxic accelerated aging to reproduce bottle aging. The volatile profile of the wines was analyzed using several chromatographic procedures, in order to provide a comprehensive evaluation of wine aroma. Aroma compounds analyzed included fermentation volatile metabolites, grape-derived aroma compounds including PFMs, and Strecker aldehydes (SA).

Results revealed that the effects of yeast on wine aroma throughout its self-life extend along three main axes:

1. A direct or indirect action on primary varietal aroma and on its evolution during wine
aging.

2. The direct production of SA during fermentation and/or their delayed formation by producing the required reagents (amino acids + dicarbonyls) for Strecker degradation
during anoxic aging.

3. Producing acids (leucidic, branched acids) precursors to fruity esters. More specifically, and leaving aside the infrequent de novo formation, the action of the different strains of yeast on primary varietal aroma takes four different forms:

1.- Speeding the hydrolysis of aroma precursors, which leads to early aroma formation without changing the amount of aroma formed. In the case of labile molecules, such as linalool, the enhancement of young wine aroma implies a short-living wine. 2.- Metabolizing the aroma precursor, reducing the amounts of aroma formed, which can be of advantage for negative aroma compounds, such as TDN or guaiacol; 3.- Transforming grape components into aroma precursors, increasing the amounts of aroma formed, as for ethyl cinnamate, leucidic acid or vinylphenols; 4.- Forming reactive species such as vinylphenols able to destroy varietal polyfunctional mercaptans.

Overall, it can be concluded that the yeast carrying alcoholic fermentation not only influences fermentative wine aroma but also affects to the wine varietal aroma, to its evolution during aging and to the development of oxidative off-odors

The growing demand for non-alcoholic beverages, driven by health-conscious consumers and shifting social norms, has positioned dealcoholized wines as a promising alternative in the global beverage industry (Akhtar et al., 2025, in press; Kakroo, 2024).

Aims: The aims of this study are to determine the influences of the local geology, mineralogy and geochemistry of surroundings, substrate and soil on the cultivation of vines, these as an additional factor of specificity and locality in the production of wine and definition of terroir, as well as for the discrimination of local variance of substrate and soil properties for the strategic management of cultivation plots and/or the evaluation of new cultivation regions, necessary within a scope of global climate change.

Il n’existe presque pas d’études qui caractérisent l’effet du climat viticole sur la typicité des vins en considérant les différents types de climats à l’échelle mondiale. Cette étude fait partie d’un projet CYTED de zonage vitivinicole. L’objectif a été de caractériser l’effet du climat viticole sur la typicité des vins sur une macro région viticole du monde.