BACKGROUND: In the present work, the flavor compounds of natural juice of bilberries were qualitatively analyzed by GC-MS, leading to the identification of trans-Hex-2-en-1-ol as one of the major 'impact aroma' compounds of this fruit. The pervaporation of trans-Hex-2-en-1-ol from diluted aqueous solutions was studied using commercial polydimethylsiloxane (PDMS) capillary membranes. The influences of solvent composition (water/ethanol mixtures), initial concentration of the aroma compound, flow rate and temperature of the feed were studied. RESULTS: High selectivity of the PDMS membrane towards the aroma compound was obtained, leading to enrichment factors in the range 100 < beta < 200. Mass transfer resistance was found to be located in the pervaporation membrane. Experimental data showed a linear dependency of the permeation flux of trans-Hex-2-en-1-ol on the differences in partial pressures of the compound across the pervaporation membrane. The permeability coefficient of the PDMS membrane to the transport of trans-Hex-2-en-1-ol was calculated as P-m,P-Hex (50 degrees C) = 7.62 x 10(-11) mol m(-1) s(-1) Pa-1. CONCLUSION: The membrane used was found to be very selective toward trans-Hex-2-en-1-ol. A model based on the solution-diffusion mechanism was applied. The mass transfer parameters needed for the design of a pervaporation process for aroma compound recovery were obtained. (C) 2008 Society of Chemical Industry.