Tangential-flow membrane clarification of Malvar (Vitis vinifera L.) wine: incidence on chemical composition and sensorial expression

Abstract

Malvar white wine (Vitis vinifera L.) was cold settled (CSW) and clarified by tangential-flow membrane filtration (TFMF). A 500 kDa molecular mass cut-off membrane was used. Filtration flux of 49-48 L/hm2 was achieved at transmembrane pressure of 0.7 bar. The treatment produced a completely clarified wine with turbidity of 0.11 NTU, but also a 10.3% loss of proteins, which could be related to the decrease of some flavour compounds. The CSW and the membrane filtered wines (MFW) were assessed by means of their aroma and phenolic composition, as well as their sensory properties. The results showed that the general physicochemical parameters and most of the analysed phenolic compounds were not or slightly (up to 7.6%) affected by the TFMF process. Nevertheless, the treatment produced an important loss of some key aroma compounds: up to 43% of fatty acid and alcohol esters and up to 26% of higher alcohols. Most affected were aroma species with higher molecular masses and lower polarities. Sensory analysis confirmed the global decrease in wine aroma. TFMF treatment produced also an increase of 52% of the wine benzaldehyde content.