«Aztec» – the new white table grape resistant variety

The main objective of this work is to study and model the impact of the polyphenolic profile on the stability and quality of wine aroma during oxidative aging.

Many of the world’s vineyard regions are located in regions of complex terrain, with the result there is significant local climate variation.

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.

La place prépondérante que prend le Massif Jurassien en Franche-Comté confère à la région un caractère montagneux qui a orienté l’agriculture vers l’élevage laitier. Cette vocation pastorale marquée et de rudes conditions climatiques sont à l’origine de la production, attestée depuis l’Antiquité, d’un fromage de réserve pour la longue période hivernale. Cette tradition fromagère, liée à des prairies naturelles, a perduré jusqu’à nos jours. La qualité et la spécificité du produit actuel, le fromage de Comté, ont été reconnues dès 1952 par l’attribution d’un label et dès 1958, par la reconnaissance d’un périmètre d’appellation d’origine contrôlée, l’A.O.C. Comté (fig. 1).

The wine yeast Saccharomyces cerevisiae can highly affect wine aromatic profile by producing and/or mediating the release of a whole range of metabolites (such as thiols, esters, and terpenes), which in turn contribute to enhanced aroma and flavor. These metabolites depend on yeast metabolism activated during fermentation which can constitute the ‘’metabolic footprint’’ of the yeast strain that carried out the process.