Factors involved in the acumulation of acetic acid inside the grapes during winemaking by carbonic maceration

Obiettivo del progetto è la valutazione dell’influenza climatica e pedologica dell’areale di Montefalco sul vitigno Sagrantino, ponendo particolare attenzione alla componente polifenolica e antocianica. Sono stati quindi messi a confronto, a partire dal 2001 fino al 2008, sei differenti zone tutte situate all’interno dell’areale DOCG Sagrantino di Montefalco; per ciascun vigneto alla vendemmia sono state effettuate analisi sui parametri analitici e sul contenuto polifenolico e antocianico delle uve. Ognuna delle sei zone è inoltre stata caratterizzata dal punto di vista pedoclimatico, valutando l’influenza del clima e della tipologia di suolo sui parametri analitici presi in considerazione.

Climate change has varied effects across French vineyards, with marked regional differences in temperature shifts. Fine-scale studies highlight significant local climate variability, emphasizing the need for precise regional characterization to adapt vineyard management at the regional scale.

Characteristics related to the climate and the soil of Montefalco in the centre of Italy have been defined in order to evaluate their influence on the red cv.

Spatial variability of vine productivity in winegrapes is important to characterise as both yield and quality are relevant for the production of different wine styles and products. The objectives were to understand how patterns of variability of Cabernet Sauvignon fruit composition changed over time and space, how these patterns could be characterised with indirect measurements, and how spatial patterns of the variation in fruit compositional attributes can aid in improving management. Prior to the 2017 vintage, 125 data vines were distributed across each of four vineyards in the Lodi American Viticultural Area (AVA) of California. Each data vine was sampled at commercial harvest in 2017, 2018, and 2019. Yield components and fruit composition were measured at harvest for each data vine, and maps of yield and fruit composition were produced for eight ‘objective measures of fruit quality’: total anthocyanins, polymeric tannins, quercetin glycosides, malic acid, yeast assimilable nitrogen, β-damascenone, C6 alcohols and aldehydes, and 3-isobutyl-2-methoxypyrazine. Patterns of variation in anthocyanins and phenolic compounds were found to be most stable over time. Given this relative stability, management decisions focused on fruit quality could be based on zonal descriptions of anthocyanins or phenolics to increase profitability in some vineyards. In each vineyard, dormant season pruning weights and soil cores were collected at each location, elevation and soil apparent electrical conductivity surveys were completed, and remotely sensed imagery was captured by fixed wing aircraft and two satellite platforms at major phenological stages. The data collected were used to develop relationships among biophysical data, soil, imagery, and fruit composition. The standardised and aggregated samples from four vineyards over three seasons were included in the estimation of ‘common variograms’ to assess how this technique could aid growers in producing geostatistically rigorous maps of fruit composition variability without cumbersome, single season sampling efforts.

Extraction of anthocyanins and tannins have been studied for two grape varieties, Carignan and Grenache, two maturation levels and two vintages, in model solutions and in wines, using UHPLC-MS/MS in the MRM mode  and HPSEC.