Relationships between temporal release of aroma compounds in a model mouthsystem and their physico-chemical characteristics

The influence of matrix composition and mastication on the temporal release of seven aroma compounds was studied in a model mouth system. 2-Butanone, diacetyl, ethyl acetate, 3-methyl-1-butanol, hexanal, 2-heptanone and ethyl butyrate were released from water and sunflower oil, with and without mast ication, for 15, 30, 60, 120, 240, 480 and 720 s. Aroma compounds were quan tified by gas chromatography/mass spectrometry. Volatile compounds were rel eased at significantly different rates. The release of hydrophobic compound s from the oil was decreased, whereas the release of the hydrophilic compou nd diacetyl was increased in comparison with the water matrix. Interactions were observed between volatile compounds and matrix, as well as between vo latile compounds and mastication. Linear release rate constants were relate d to physico-chemical characteristics, such as molecular weight, boiling po ints, vapour pressures, octanol-water, gas-water and gas-oil partition coef ficients. The octanol-water partition coefficients correlated reasonably we ll with linear release rate constants for the release from water and oil wi thout mastication, and from water with mastication. The other physico-chemi cal characteristics correlated poorly with linear release rate constants. ( C) 2000 Elsevier Science Ltd. All rights reserved.