Study on improvement of the quality in Chinese new-type liquor by pervaporation with polydimethylsiloxane membrane

A composite polydimethylsiloxane (PDMS) membrane was used to separate aroma compounds from Chinese new-type liquor by pervaporation at 30, 35 and 40C and 10-mmHg downstream pressure. The gas chromatography analysis of aroma compounds in the retentate and permeate showed that PDMS membrane had excellent separation performance. Separation efficiencies for five kinds of esters (except ethyl lactate) and acetal in the original liquor are 100%, over 70% for alcohols (except methanol) and above 87% for aldehyde. The average flux for ethanol reached 3,539 g/m(2) . h at 40C. Sensory analysis of the separated ingredients indicates that the sensory quality of the new liquor was significantly superior to that of the original liquor. Experiments suggest that pervaporation is a promising technique for the improvement of Chinese new-type liquor in terms of its flavor.