Membrane separation technology for the reduction of alcoholic degree of a white model wine

The reduction of the alcoholic degree of a white model wine by means of membrane separation technology was studied in this work. Reverse osmosis and nanofiltration are the most promising processes for the production of wines with low alcohol content, because they can operate at low temperature and thereby preserve the aromatic profile of wine. Assuming that the rejection of the main wine compounds (i.e. acids, sugars and tannins) is very high, the aim of this research was to study the permeation of several characteristic aroma compounds in the white model wine. Permeation was conducted in batch retentate-recycling mode with two reverse osmosis and one nanofiltration membranes previously conditioned with a 12 ml/100 ml aqueous ethanol solution. Aroma compounds were identified by gas chromatography coupled to quadrupolar mass selective spectrometry. A mathematical model allowed calculation of the aroma compound concentrations in the retentate and permeate streams as a function of permeate volume and the concentration of solutes in the diluted final wine at 8 ml/100 ml ethanol concentration.