Pre-fermentative maceration with SO2 enhanced the must aromatic composition

Abstract

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.

Keywords: Extraction; Grape varietal aroma; Pre-fermentative compounds; Sulphur dioxide; Volatile composition.