Polyphenols in kombucha: impact of infusion time on extraction and investigation of their behavior during “fermentation”

Wine perception results from the interaction between the wine and its intrinsic and extrinsic characteristics and the experience [1], background and beliefs of the consumer [2,3]. Among all of the factors affecting wine perception, in this study we focused on culture and cognitive processes, working under the hypothesis that higher familiarity with wines would induce higher perceived quality. Furthermore, we hypothesised that culture would influence the verbalisation of wine properties associated with the different experiences of consumers from different cultures.

Hydroxytyrosol (HT) is well known for its potent antioxidant activity and anticarcinogenic, antimicrobial, cardioprotective and neuroprotective properties. One possible explanation to its origin in wines is the synthesis from tyrosol, which in turn is produced from the Ehrlich pathway by yeasts. This work aims to explore the factors that could increase the final content as the initial concentration of yeast assimilable nitrogen (YAN) and sugar. Two different concentrations of YAN were proved between 210mg/L and 300 mg/L. Additionally, two different concentrations of sugar were used: 100g/L and 240 g/L. Alcoholic fermentations in synthetic must were performed with the strain QA23.

A large genetic diversity exists among V. vinifera varieties, but also among cultivated rootstocks. This diversity is important to adapt plant material to different environmental conditions

The maturation patterns process has been very studied. In particular the modelization of the sugars and titratable acidity during the ripening period was an important approach, in particular for the prediction of harvest date (Barillere et al., 1988; Jourion et al.,1987; Maujean et al., 1983; Scienza, 1989). In Oltrepò Pavese, the widest viticultural district of Lombardy – Northern Italy – (about 15000 hectares), grape maturation trends shows high variability, due to the large variation in environmental characteristics of vineyards (altitude, exposure, soil type, mesoclimate) and to “cultivar x environment” interaction.

Les approches du terroir en tant qu’entité géographique (zonages) connaissent un développement accru récent en lien avec l’essor des SIG. Les méthodes, les objectifs et les critères utilisés varient considérablement selon les études.