Dealcoholizing wine by membrane separation processes

The present work studies the use of membrane separation processes for producing wine with low alcohol content. Several membranes of reverse osmosis (CA995PE from Alfa Laval) and nanofiltration (NF99 HF, NF99, NF97 from Alfa Laval and YMHLSP1905 from Osmonics) were used for removing ethanol from a 12 vol.% red wine, in diafiltration mode, whereas pervaporation membranes of polyoctylmethylsiloxane supported in polyetherimide (POMS/PEI) from GKSS were used to recover the aroma compounds before the dealcoholization step, and adding them back to the dealcoholized wine. YMHLSP1905, NF99 and NF99 HF nanofiltration membranes showed higher effectiveness in alcohol removal from wine, due to their good permeability to ethanol and high aroma compounds' rejection, resulting in dealcoholized wine samples with promising organoleptic properties. The addition of pervaporated aroma compounds to the dealcoholized wine samples increased the flavour sensations during the wine tasting, making this combined process the one that originates the best dealcoholized wine samples.Industrial relevanceThe alcohol removal from wines has a great importance in the beverages industry due to the increasing demand on the non-alcoholic drinks market and also due to the increase of ethanol content of wine. This fact results namely from global warming or oenological practices and some winemakers have to pay taxes if ethanol content overcomes 14.5 vol.%. Membrane processes can be used for removing the ethanol from a regular wine. The results of this study indicate that nanofiltration and pervaporation are effective for dealcoholizing wine and preserving its original characteristics.

Research highlights
► Nanofiltration and reverse osmosis promote wine dealcoholization.
► Ethanol content of wine is decreased from 12 vol.% to 7–8 vol.%.
► Nanofiltration membranes tested are more effective for ethanol removal.
► Pervaporation improves aroma profile of dealcoholized samples.