Impact of cover crop in vineyard on the musts volatile profile of Vitis vinifera L. Cv Syrah

País grape has been estimated to arrive to Chile almost 500 years ago, being the first strain grown in this country. Traditionally, this grape has been used to mix with other varieties, to produce poor quality wines, but today is beginning to be used in the production of high quality wines. However, very little is known about the chemical characteristics of this variety. The aroma is one of the most important quality attributes of wine. Volatile compounds of this beverage may come from the grape (varietal aromas), from the fermentation process, from the ageing. The aromatic compounds are found in the grape in two forms: as free volatile compounds and as non-volatile compounds. The last ones, are aroma precursors present mainly as glycoconjugates formed by a sugar and an aglycone…

Varietal Riesling aroma relies strongly on the formation and liberation of bound aroma compounds. Floral monoterpenes, green C6-alcohols, fruity C13-norisoprenoids and spicy volatile phenols are predominantly bound to disaccharides, which are produced and stored in the grape berry during berry maturation. Grape processing aims to extract maximum amount of the precursors from the berry skin to increase the potential for a strong varietal aroma in the wine. Subsequent yeast selection plays an important part in this process.

With alcohol consumption steadily declining, the growing popularity of dry january, a fiercely competitive environment, high dry matter inflation, economic upheavals, commercial uncertainties… The wine industry must adapt and offer products that meet consumer expectations, without denying their historical singularities.

Gum arabic is composed of a polysaccharide rich in galactose and arabinose along with a small protein fraction [1, 2], which gives its stabilizing power with respect to the coloring substances or tartaric precipitation of bottled wine. It is a gummy exudation from Acacia trees; the products used in enology have two possible botanical origins, i.e. Acacia seyal and Acacia senegal, with different chemical-physical features and consequently different technological effects on wines. The aim of this work is to evaluate the feasibility of discrimination of commercial gums Arabic between their two different sources, on the basis of the absorption of the Fourier Transform Infrared (FT-IR) spectra of their aqueous solutions, in order to propose an extremely rapid and cost-saving method for quality control laboratories.

La prise en compte des paysages viticoles dans le développement durable ou l’aménagement du territoire est un thème non négligeable pour la valorisation de la filière viti-vinicole à l’échelle d’une exploitation ou d’une A.O.C.