Pre-fermentative maceration with SO2 enhanced the must aromatic composition.

SO2 is the additive most used in winemaking, due to its antioxidant and antiseptic activities. There have been several studies focused on these activities; however, there are hardly any studies that address its role as extractant. Therefore, the objective of this work was to study the effect of SO2 on the must volatile composition after a pre-fermentation maceration. The results showed that the influence of SO2 on the extraction of the two most important families of varietal compounds, terpenoids and C13 norisoprenoids, was different: the content of total terpenoids increased by 95%, while for the total of C13 norisoprenoids no significant differences were observed. The other three families of volatile compounds studied, benzenoid compounds, esters, and C6 compounds, were found in greater quantity in the samples with SO2, increasing by 51%, 164%, and 45%, respectively. Consequently, SO2 can enhance the must aromatic composition of neutral varieties, such as Tempranillo.