L’évolution des Appellations d’Origine aux Etats-Unis

Il a été souvent démontré (Seguin, 1970), que les meilleurs terroirs sont ceux qui présentent pendant la période de maturation du raisin, une régulation et une limitation de l’alimentation hydrique de la vigne. Si on s’intéresse aux facteurs influençant ce régime hydrique, on constate le rôle prépondérant du taux d’éléments grossiers non poreux qui limitent la réserve utile du sol en diminuant le taux de terre fine. De plus, ces éléments grossiers jouent également un rôle au niveau du pédo-climat thermique car leur conductivité thermique et leur chaleur spécifique sont plus élevées que celles de la terre fine. Ainsi le sol se réchauffera et se refroidira plus rapidement (Saini et McLean, 1967), (Gras, 1994).

Climate change (CC) is altering grape/wine composition, leading to challenges in maintaining wine sensory quality.

Agiorgitiko (Vitis vinifera L. cv.) is the most widely cultivated indigenous red grape variety in Greece, known for the production of Protected Designation of Origin Nemea wines.

Red grape pomace, a waste from wine production, can be valorised by extracting polyphenols, high-added value compounds used in cosmetics or oenology. For use at an industrial level, using green extraction techniques, pomace need to be stored before being processed. The aim of this study is to test various storage conditions in order to maintain high level of polyphenols over 180 days, while keeping storage cost economically interesting. In a first step, different storage conditions (ambient temperature or cooled (4°C) temperature, anaerobic (saturation with N2) or aerobic conditions, and addition of sulphur dioxide (SO2)) were compared on small samples (1 kg) packed in plastic pockets. The quality of storage was assessed by following the optical density of the pomace extract at 280 nm (DO 280 expressed as mg/l eq gallic acid), which is an indication of the amount of remaining extractable polyphenols.

The availability of water for irrigation is usually greater at the beginning of spring than in the following months, until the end of summer, in most regions of Spain.