INSIGHTS ON THE ROLE OF GENES ON AROMA FORMATION OF WINES

The chemistry of wine is notably complex and is modified by ageing of the bottles. The composition of wines is the result of vine production (under the influence of vintage, climate and soils); yeast production (under the influence of juice composition and fermentation management); lactic bacteria production (under the influence of young wine composition and malolactic fermentation management); and of the ageing process either in vats, barrels or bottles or both. The composition is linked to the quality perceived by consumers but also to their origin, sometimes associated to the “terroir” concept.

The own-rooted vineyard of Santorini is a unique case of vineyard worldwide that is been cultivated for thousands of years. On the island’s volcanic soil, the vines are still cultivated with traditional techniques, which are adapted to the specific and extreme weather conditions that prevail on it. While climate change is a reality in the Mediterranean region, will Santorini vineyard endure its impact? The study of the traditional training systems, techniques and vine density, as well as the application of sustainable solutions (cover crops and use of kaolin etc.) revealed sustainable methods for the adaptation of the local viticulture to new climatic phenomena that tend to be more and more frequent in the region due to climate change.

Nitrogen (N) nutrition of the vineyard strongly influences the must and the wine compositions. Several chemical markers present in wine (i.e., proline, succinic acid, higher alcohols and phenolic compounds) have been proposed for the cultivar Chasselas, as indicators of N deficiency in the grape must at harvest [1]. Grape genetics potentially influences the impact of N deficiency on grape composition, as well as on the concentration of potential indicators in the wine. The goal of this study was to evaluate if the che- mical markers found in Chasselas wine can be extended for other white wines to indicate N deficiency in the grape must.

After bottling, the wine continues to evolve during storage. The choice of the stopper is an important factor in this evolution. In addition to the oxygen permeability of the closure, the migration of stopper compounds into the wine can also have an impact on the wine organoleptic properties. Many studies have shown that transfers of volatile compounds from the stoppers into the wine can happen depending on the type of closure used (1). Moreover, when cork-made stoppers are used, the migration of phenolic compounds from the stopper into the wine can also occur (2, 3).

Aging red wines in oak barrels is an expensive and laborious process that can only be applied to wines with a certain added value. For this reason, the use of oak alternatives coupled with micro-oxygenation has progressively increased over recent years, because it can reproduce the processes taking place in the barrels more economically and quickly [1]. Several studies have explored how oak alternatives [2-5] can contribute to wine composition and quality but little is known about the influence of their thickness.