Influenza delle componenti climatiche e pedologiche sulla variabilità dei contenuti polifenolici in alcuni ambienti vitati della DOCG Sagrantino di Montefalco

Valpolicella is a famous Italian wine-producing region. Wines produced in its different sub-regions are believed to be aromatically different, as confirmed by recent studies in our laboratory. Aging is a very common practice in Valpolicella and it is required by the appellation regulation for periods up to four years require wines. The aim of this study was to investigate the evolution, during aging, of volatile chemical composition of Valpolicella wines obtained from grapes harvested in different sub-regions during different vintages.

Aims: Wine perceived quality lies on a number of different factors. Among these, sensory features, which are in turn dependent on chemical composition, play a primary role. There is traditionally a great emphasis on producing wines that have specific sensory profiles, particularly aroma, that reflect identity features connected to the place and the variety of origin. In the case of high quality

The forchlorfenuron (CPPU) application is recommended in table-grape after fruit-set to boost berry sizing, albeit growers also apply CPPU during pre-flowering with controversial advantages. We examined the effect of single (BBCH 15) and double (BBCH 15 and 57) CPPU applications (2.25 mg/L a.s.) in a commercial vineyard. At each time, 75-100 bunches belonging to 6-9 vines were sprayed, and compared with unsprayed (CTRL). Leaf stomatal conductance (gs), cluster stem diameter and length were measured. At harvest, 25 berries/repetition were sampled for chemical composition, BSN incidence was counted (N° necrotic laterals/10 cm of stem) in 40 bunches/repetition. To test the role of air VPD on mineral composition, at BBCH 77, 50 CTRL clusters were bagged to induce a low VPD.

Current changes of ecoclimatic indicators may cause significant variation in grapevine phenology and grape ripening. Climate change modifies several abiotic factors (e.g. temperature, sunlight radiation, water availability) during the grapevine growth cycle, having a direct impact on the phenological stages of the grapevine, modulating the metabolic profile of berries and activating the synthesis and accumulation of diverse compounds in the skin of berries, with consequences on the composition of the grapes.
The influence exerted by different meteorological conditions, during three consecutive years (2020-2022) on secondary metabolites such as the polyphenolic profile of Grignolino grapes was investigated. The samples were collected from three vineyards characterized by different microclimatic conditions mainly related to the vineyard aspect and to a different age of the plants.

Grape ripening is a critical phenophase during which many metabolites driving wine quality are accumulated in berries. Major changes in berry composition include a rapid increase in sugar and a decrease in malic acid content and concentration. Its duration is highly variable depending on grapevine variety, climatic parameters, soil type and management practices.