Alternative fate of varietal thiols in wine: identification, formation, and enantiomeric distribution of novel 1,3-oxathianes

Several Uruguayan wineries have begun to produce wines with minimal intervention, to increase the sustainability of their vineyards and wines. These wines are characterized by the minimum intervention in the management of the vineyard, its harvest, vinification, conservation and aging1,2. Sulfur dioxide (SO2) is not used or is used in reduced doses, although chitosan can be substituted or supplemented1. The objective of this research is to evaluate SO2 reduction or replacement options adapted to the production of Tannat red wines with minimal intervention. Vinification of the Tannat grapes with autochthonous yeasts (LN) was carried out during the 2023 vintage.

Resilience and sustainability are two fundamental concepts in the sustainable development of the wine sector, being closely interconnected.

G.r.a.s.p.o. Is not only the acronym for gruppo di ricerca per la salvaguardia e preservazione dell’originalità viticola di ogni territorio (‘research group for the safeguard and preservation of the originality of every territory’s grapes’), and is not just the italian synonym for ‘raspo’ (‘peduncle’) as treccani dictionary mentions: in the veneto dialect it is the whole bunch of grapes.

The production of high-quality wines requires the use of high-quality grapes. Some compounds originating from grapes may negatively influence the odour and flavour of the resulting wine in their original form or as precursors for off-odours and –flavours. Therefore, a rapid evaluation of the grapes directly upon receival at the winery is advantageous. Up to now, grape aroma is mainly evaluated by tasting, however, this leads to subjective results. The use of near-infrared (NIR) spectroscopy allows a rapid, objective and destruction-free analysis without previous sample preparation. Moreover, the measurement can be integrated into an existing process without additional sampling.

To characterize a wine, the most frequently used criteria describe its color, its origin, the grape varieties from which they come, or even for white wines its residual sugar content (dry, semi-dry, sweet). In france, the system of appellations of origin set up in 1919 was initially based solely on the notoriety and origin of the wines. But given the unfavorable consequences that this lack of details generated, the public authorities quickly integrated in 1927 into the “capus” law criteria for access to designations of origin, relating to the specific characteristics of the soils of the vineyards and the grape varieties used, in particular exclusion of interspecific hybrid varieties. In 1935 the creation of the aoc system confirmed the interest in precisely defining all the production conditions that must be implemented to be able to claim the benefit of an aoc, and grape varieties were an essential condition for acquisition.