Analyse du rôle du terroir dans la définition d’une appellation d’origine

With growing consumer interest in products without chemical additives, limiting the use of sulfites is a priority for the wine industry. Bioprotection is a biological alternative that avoids or reduces the risks of alterations that have a negative impact on the organoleptic quality of wines and, ultimately, on their acceptability to consumers. bioprotection can also provide a response to the risks of microbiological deviations, which are increased both by climate change and by the organization of harvesting operations, which increasingly include the use of multi-bins filled at the vine, exposing the harvest to sometimes high temperatures for longer periods of time.

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.

Consumers typically prefer wines with floral and fruity aromas over those presenting green-pepper, vegetal or herbaceous notes. Pyrazines have been identified as causatives for herbaceous notes in wines, especially Bordeaux reds. However, pyrazines are not universally responsible for herbaceousness, and several other wine volatile compounds are known to produce distinct vegetal/herbaceous aromas in wines. Specifically, volatile aldehydes elicit sensations of herbaceousness or grassiness and have been described in wines well above their perception thresholds.

Downy mildew (Plasmopara viticola) is a fungal pathogen that causes a destructive disease in grapevines (Vitis vinifera).

The composition of grape berry cell walls was studied on two grape varieties, two years and two maturation levels at the same time as the extraction of anthocyanins and tannins. The chemical composition of skins, seeds, and pulps, focused on polyphenols and polysaccharides, was compared to the chemical composition in polyphenols after extraction from the skins in model solutions or after wine making of the berries. Polyphenols were mainly characterized by UPLC-MS and HPLC-SEC. Polysaccharides were characterized by analysis of the neutral sugar compositions, and also by the CoMPP (comprehensive micropolymer profiling) analysis, a new method which targets the functional groups of cell wall polysaccharides.