IMPACT OF CLIMATIC ZONES ON THE AROMATIC PROFILE OF CORVINA WINES IN THE VALPOLICELLA REGION

During wine aging many compositional changes take place. In particular, aroma undergoes dramatic modifications through a wide range of reactions that to date are only partly understood. Italy owns one of the largest ampelographic heritages worldwide, with over three-hundred different varieties. Among these, many white grapes are employed for the production of dry still white wines. Some of these wines are consumed young while others are more prone to aging. For many of these wines, the aging patterns related to volatile composition are still unknown.

From the chemical angle, Champagne wines are complex hydro-alcoholic mixtures supersaturated with dissolved carbon dioxide (CO₂). During the pouring process and throughout the several minutes of tasting, the headspace of a champagne glass is progressively invaded by many chemical species, including gas-phase CO₂ in large majority. CO₂ bubbles nucleated in the glass and collapsing at the champagne surface act indeed as a continuous paternoster lift for aromas throughout champagne or sparkling wine tasting [1]. Nevertheless, inhaling a gas space with a concentration of gaseous CO₂ close to 30% and higher triggers a very unpleasant tingling sensation, the so-called “carbonic bite”, which might completely perturb the perception of the wine’s bouquet.

Glutathione is a natural tripeptide composed of l-glutamate, l-cysteine and glycine, found in various foods and beverages. In particular, glutathione can be found in its reduced (GSH) or oxidized form (GSSG) in must, wine or yeasts¹. Numerous studies have highlighted the importance of GSH in wine quality and aging potential². During winemaking, especially during aging on lees, GSH helps prevent the harmful effects of oxidation on the aroma of the wine³. Nevertheless, the amounts of GSH/GSSG present in wine lees are often unknown and the choice of operating conditions (quantity of lees and aging time) remains empirical.

Lipids are a diverse group of organic compounds essential for living systems. They are vital compounds for yeast which makes them an important modulator of yeast metabolism in alcoholic fermentation. This study presents a comprehensive lipidome analysis of wine samples from the Vitis vinifera L., Maraština. The fermentation trails were set up in monoculture with different indigenous yeast strains selected from a collection of native yeasts established at the Institute for Adriatic Crops and Karst Reclamation in 2021, previously isolated from Croatian Maraština grapes: Metschnikowia pulcherrima, Metshnikowia sinensis/shanxiensis , and Metschnikowia chyrsoperlae.

Mycobiota encountered from vine to wine is a complex and diversified ecosystem that may impact grape quality at harvest and the sensorial properties of wines, thus leading to off-flavors [1-3]. Among known off-flavors in wine, fresh mushroom aroma (FMA) has been linked to some mold species, naturally pre-sent on grapes, producing specific volatile organic compounds (VOC) [4-5]. The most well-known are 1-octen-3-ol and 1-octen-3-one, although many other VOC are likely involved. To better understand the FMA defect, biotic and abiotic factors impacting growth kinetics and VOC production of selected fungal species in must media and on grapes were studied.