Influence of Sulfur Dioxide on the Formation of Aldehydes in White Wine

Abstract

Relatively little is known about the effects of sulfur dioxide on the general formation of flavors during fermentation. Volatile, saturated aldehydes are an important class of aroma compounds that can impact the sensory characteristics of the final wine. This study quantified the saturated aldehydes C1 through C9 formed during fermentation of white juice with different concentrations of added sulfur dioxide. Results showed that maximum concentrations of acetaldehyde (C2), 2-methyl-1-propanal (isobutanal, i-C4), and 3-methyl-1-butanal (isovaleraldehyde, i-C5) were affected by an increase in sulfur dioxide concentration during fermentation. Changes in aldehyde production patterns were observed for the different sulfur dioxide additions. Final concentration for acetaldehyde (C2) was also affected by an increase in sulfur dioxide concentration. Production patterns of formaldehyde (C1), propanal (C3), pentanal (C5), hexanal (C6), and heptanal (C7) were only slightly affected by the different levels of sulfur dioxide up to 150 mg/L, but when the sulfur dioxide addition reached 200 mg/L, aldehyde production patterns and concentrations were affected. Butanal (C4) concentrations remained constant independent of sulfur dioxide additions, and octanal (C8) and nonanal (C9) were not found in significant amounts.