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

This study investigates the recovery of a wine-must aroma profile, formed b y Saccharomyces cerevisiae during a muscatel wine-must fermentation, using organophilic pervaporation. Experiments were carried out along two independ ent, but organoleptically similar, fermentations. The wine-must samples and the aroma concentrates obtained were characterized organoleptically by a s ensory panel and analytically with regard to eight major wine-must componen ts: four alcohols; th ree esters; and one monoterpenic compound. Pervaporat ion 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 concent rations in the wine-must caused a dramatic enrichment of two esters in the permeate, whereas other components investigated seemed unaffected. This shi ft resulted in an unbalanced aroma. In conclusion, it was shown that organo philic pervaporation can be highly suitable for the continuous recovery of very complex and delicate aromatic profiles produced during microbial ferme ntation. (C) 1999 John Wiley & Sons, Inc.