Evaluation of mannoprotein formation by different yeast strains by enzymatic analysis of mannose and tribological estimation of astringency

This study investigates the chemical and sensory profiles of white wines produced from disease-resistant hybrid grape cultivars (DRHGCs) compared to traditional Vitis vinifera L. cultivars in South Tyrol, Italy.

Developments in high-throughput sequencing (HTS) technologies allow us to obtain large amounts of microbial information from wine and must samples. Thus approaches, that are aimed at characterising the microbial diversity during fermentation, can be enhanced, or possibly even replaced, with HTS-based metabarcoding. To reduce experimental biases and increase data reproducibility, we compared 3 DNA extraction methods by evaluating differences in the fungal diversity with Riesling alcoholic fermentation samples at four different vineyards. The fungal diversity profiling was done using the genetic markers ITS2 and D2 using metabarcoding. The extraction methods compared consisted of a commercial kit, a recently published protocol that includes a DNA enhancer, and a protocol based on a buffer containing common inhibitor removal reagents. All methods were able to distinguish vineyard effects on the fungal diversity, but the results differed quantitatively.

Nous avons peu d’informations sur les cépages cultivés dans la région de la Campania (sud de l’ltalie). En particulier insuffisant sont les études sur les besoins thermiques de tels cépages.

ln the current work, phenolic and cellular maturation curves were used to assess the degree of adaptation of the cultivar Cabernet sauvignon to the sites under esamination. Five wine­-producing zones with different pedoclimatic characteristics and latitudes were considered (Marche, Toscana, Emilia, Friuli and Slovenia).

Quercetin-3-glucoside, a grape flavonol defence metabolite, is extracted during winemaking and may undergo subsequent degradation in wines. Hydrolysation reactions lead to the formation of the aglycone quercetin, which presents limited solubility in the wine matrix and can induce visible precipitations.