Incidence des conditions de conservation des vins blancs sur leur teneur en composés soufrés volatils

Abstract

Dans ce travail, nous avons etudie l’incidence de quelques parametres de conservation des vins issus des cepages blancs grecs, Batiki et Rhoditis, sur leur teneur en composes soufres volatils. Il est demontre que le stade du sulfitage des vins nouveaux joue un role important sur la formation de ces substances, ainsi que l’aeration qui entraine leur diminution. De plus, la conservation des vins en barrique ou en cuve, avec les lies ou non, influence d’une maniere differente la teneur des vins en substances soufrees volatiles. Influence of white wine conservation conditions on the levels of volatile sulphur compounds In the present study, the effects of various parameters of white wine conservation on the level of volatile sulphur compounds were examined. Wines from the Greek white cvs Batiki and Rhoditis were fermented. H2S was analysed colorimetrically, the more volatile sulphur compounds by headspace-gas chromatography (GC) coupled with flame photometry detection (FPD) and the less volatile sulphur compounds by liquid extraction-GC/MS. The best time to sulphurize a young wine is 5-6 d after the end of alcoholic fermentation in order to avoid the accumulation of sulphur substances, especially in wines intended to age on lees, Aeration of wine causes a notable decrease of the more volatile sulphur compounds, whereas the diminution is less important for the less volatile sulphur compounds. Furthermore, the amount of volatile sulphur compounds is affected by the conservation of wines in barriques or in stainless tanks, the duration of contact of wine with its lees, as well as the duration of conservation.