Observatoire Grenache en Vallée du Rhône: incidence du terroir sur certains précurseurs d’arômes et substances volatiles

Bottle ageing is considered essential for most premium red wine production. An important aim of bottle ageing of wine is to achieve a balance between the oxidative and reductive development. This is typically evaluated by the accumulation of aldehyde compounds (causing oxidative off-flavour) and sulfur-containing compounds (causing reductive off-flavour) in the wine [1]

The experimental studies conducted in the eastern Georgia in Sagarejo administrative district on the foothills of the southern slope of Tsiv-Gombori range reveal the possibility of enlarging Manavi traditional specific zone to the north-west (from Giorgitsminda to Khashmi), at 500-750 m above sea level.

Tyrosol (TYR) and hydroxytyrosol (HYT) are bioactive phenols present in olive oil and wine, basic elements of the Mediterranean diet. TYR is reported in the literature for its interesting antioxidant, cardioprotective and anti-inflammatory properties. In wine, its concentration can reach values as high as about 40 mg/L
[Pour Nikfardjam et al. 2007] but, more frequently, this phenol – derived from yeast metabolism of tyrosine during fermentation – is present at lower levels, generally higher in red wines compared to whites. HYT was measured for the first time by Di Tommaso et al. [1998] in Italian wines – with maximum values of 4.20 mg/L and 1.92 mg/L for red and white wines, respectively – while definitely lower concentrations have been found later in Greek samples.

Grape volatile compounds are mainly responsible for wine aroma, so it is important to know the va-rietal aromatic composition throughout ripening process. Currently, there are no tools that allow mea-suring the aromatic composition of grapes, in intact berries and periodically, throughout ripening, in the vineyard or in the winery. For this reason, this work evaluated the use of near infrared spectroscopy (NIR) to estimate the aromatic composition and total soluble solids (TSS) of Tempranillo Blanco berries during ripening. For this purpose, NIR spectra (1100-2100 nm) were acquired from 240 samples of in-tact berries, collected at different dates, from veraison to overripening.

Cannonau variety is historically grown in a large Sardinia area (Jerzu district) and the vineyards are planted both in the plane and in the sloped hills reaching also 650 m of altitude a.s.l. Thus, in order to discover how climate, soil diversity and growing traditions could account for differences in grape and wine quality, this trial was carried out.