Dimethyl sulfide: a compound of interest from grape to wine glass

Abstract

The overall quality of fine wines is linked to the development of “bouquet” during wine bottle ageing¹. Several chemical reactions, occurring in atmosphere protected from oxygen, are favourable to the formation and preservation of sulphur compounds such as dimethyl sulfide (DMS). DMS accumulate in wines thanks to hydrolysis of its precursors (DMSp) mainly constituted by S-methylmethionine (SMM) already identified in grapes^2,3. During alcoholic fermentation (AF), a part of SMM is degrade by the action of yeast. Hence, the whole of DMSp is not given to the young wine⁴. However, the presence of DMS in wines in linked with the expression of bouquet typicity of Bordeaux red wines⁵ and is implicated to aromatic nuances such as “truffle” and “blackberry”⁶ notes. Also, it can influence the tasting experience to give sensory polymorphism to wines⁷. Even if DMS seems to be an essential contributor to aged wine aroma, some points have never been explore. This have invited us complete the knowledge on the modulations of the DMS levels from grapes to the wine service. 

Various experiments were set up to answer at our hypotheses. DMSp was measured on many Bordeaux red musts, also during AF and on wines and wine model solution.

We observed the increase of DMSp levels during merlot and cabernet-sauvignon ripening. Even if a difference of accumulation seems to exist between varieties and localization, the real amount of DMSp accumulated is similar between all samples. Among all studied parameters, a link was measured between DMSp and YAN. Then, winemaking process is a key step because DMSp is consumed at the beginning of the AF and consumption depends of the levels of YAN and sometimes the yeast strain. About wine, DMS volatility is modulated by phenolic matrix. Our study highlight a form of DMS linked with grapes tannins. It sensorial impact have been partially studied but the results suggest that during tasting, a progressive release of DMS from a linked form could be implicated in the generation of many sensorial images perceived and contribute to the complexity of wine bouquet. 

¹ Peynaud, E., 1980
² Loscos, N et al., 2008
https://doi.org/10.1016/j.aca.2007.11.033
³ Segurel et al., 2005
https://doi.org/10.1021/jf048273r
⁴ Dagan, L., 2006
⁵ Picard, M. et al., 2015
https://doi.org/10.1021/acs.jafc.5b03977
⁶ Lytra, G. et al., 2014
https://doi.org/10.20870/oeno-one.2014.48.1.1660
⁷ Lytra, G. et al., 2016
https://doi.org/10.1016/j.foodchem.2015.07.143