Caractérisation du terroir en Espagne : méthodologie de l’évaluation et de la validation

According to the Directive EU 2019/633, European Union settled a minimum harmonised framework of rules to ensure the prohibitions of unfair commercial practices in business to business relationship of agrifood sector.

Quercetin precipitation has become an increasingly common issue in red wine, often resulting in visually unpleasant sediments and diminished product quality.

In 1979, the so-called “french paradox” was proposed, that is, a correlation between wine consumption, a diet rich in saturated fats, and a low mortality from coronary heart disease. On the other hand, it has also been described that alcohol consumption has negative effects on aging and increases the risk of liver cirrhosis and cancer. However, both hypotheses are based on population studies that may present distortions due to multiple factors (geographic, diet, smoking, socioeconomic level, etc.).

L’activité photosynthétique et les relations hydriques de plantes de Syrah sur R99 un mois après la véraison ont été étudiées dans un vignoble de la région de Stellenbosch. Le vignoble, planté à 2,75 entre rangs et 1,5 m sur le rang, sur un sol de type Glenrosa, était en pente et exposé a l’ouest: pour les rangs on avait adopté une orientation nord

Several classes of flavonoids, such as anthocyanins, flavonols, flavanols and flavones, undergo a slow H/D exchange on aromatic ring A, leading to full deuteration at positions C(6) and C(8). Within the flavanol class, H-C(6) and H-C(8) of catechin and epicatechin are slowly exchanged in D2O to the corresponding deuterated analogues; even quercetin, a relevant flavonol representative, shows the same behaviour in a D2O/DMSOd6 1:1 solution. Detailed kinetic measurements of these H/D scrambling processes are here reported by exploiting the time-dependent changes of their peak areas in the 1H-NMR spectra taken at different temperatures. A unifying reaction mechanism is also proposed based on our detailed kinetic observations, even taking into account pH and solvent effects. Molecular modelling and QM calculations were also carried out to shed more light on several molecular details of the proposed mechanism.