Recovery of aroma compounds from a wine-must fermentation by organophilic pervaporation

Abstract

This study investigates the recovery of a wine-must aroma profile, formed by Saccharomyces cerevisiae during a muscatel wine-must fermentation, using organophilic pervaporation. Experiments were carried out along two independent, but organoleptically similar, fermentations. The wine-must samples and the aroma concentrates obtained were characterized organoleptically by a sensory panel and analytically with regard to eight major wine-must components: four alcohols; three esters; and one monoterpenic compound. Pervaporation performance was studied under fermentation conditions, and the permeate concentration, partial fluxes, and enrichment of the respective compounds were determined. The muscatel wine-must aroma profile was recovered purely and faithful to its origin between wine-must densities of 1075 and 1055 g L. At the beginning of the fermentation, too few aromas were present in the must for recovery. Toward the end of the fermentation, high ethanol concentrations in the wine-must caused a dramatic enrichment of two esters in the permeate, whereas other components investigated seemed unaffected. This shift resulted in an unbalanced aroma. In conclusion, it was shown that organophilic pervaporation can be highly suitable for the continuous recovery of very complex and delicate aromatic profiles produced during microbial fermentation.