Impact of aging on dimethyl sulfide (DMS) in Corvina and Corvinone wines

Different from wild species in arid and semiarid conditions, cultivated species are very sensitive to drought and, beyond some stress thresholds, food production is not possible

Vine clone selection aims at the survival of clones with particularly desireable attributes for the production of high quality wines. The purpose of this research was to study the enological potential of the clones of Greek indigenous grape varieties over two vintages, 2018 and 2019.
METHODS: Two clones of the white grape varieties Moschofilero (E26 and E27), Assyrtiko (E11 and 16), Roditis (25E16 and 02E1E21) and two clones of the red grape varieties Xinomavro (19 and E2E30) and Agiorgitiko (03E40 and 41E47) were vinified under the same protocol for the white wines and common for the red wines in 2018 and 2019. The resulting products were studied for several enological parameters such as alcohol content, volatile acidity, pH, total phenolics, anthocyanins and tannins for the red wines, as well as browning tests for the white wines. The aroma profile of these ten samples was investigated through sensory analysis with intensity rating of individual attributes on a five-point scale by a trained panel.

During the tasting of a fine, old wine, the aromas generated in the glass are intertwined in an intimate, complex manner, expressing the fragrance of the aging bouquet. This aging bouquet, which develops during bottle storage through a complex transformation process, may result in a broad palette of nuances. Among these, undergrowth, truffle, toasted, spicy, licorice, fresh red- and black-berry fruit and mint descriptors were recently identified as features of its olfactory representation for red Bordeaux wines. Although a targeted chemical approach focusing on volatile sulfur compounds revealed the role played by dimethyl sulfide, 2-furanmethanethiol, and 3-sulfanylhexanol as molecular markers of the typicality of the wine aging bouquet of red Bordeaux wines, its chemical transcription has only partially been elucidated.

The gustatory balance of dry wines is centered on three flavors, sourness, bitterness and sweetness. Even if certain compounds were already identified as contributing to sweetness, some taste modifications remain largely unexplained1,2. Some empirical observations combined with sensory analyzes have shown that an increase of wine sweetness occurs during post-fermentation maceration³. This step is a key stage of red winemaking during which the juice is left in contact with the marc, that contains the solid parts of the grape (seeds, skins and sometimes stems). This work aimed to identify a new taste-active compound that contributes to this gain of sweetness.

The effect of two rootstocks of different drought tolerance (1103 Paulsen and 3309 Couderc) on sap flow, water relations and gas exchange of cv. Xinomavro (Vitis vinifera L.) was investigated during the 2005 season in Naoussa, Greece. Soil was maintained at field capacity for both rootstock treatments until mid July when a restricted water regime was applied by irrigation cutoff. Sap flow diurnals for the Xinomavro-1103P combination showed a rapid decrease of flow after midday, under water stress conditions.