Relationships between temporal release of aroma compounds in a model mouth system 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 mastication, for 15, 30, 60, 120, 240, 480 and 720 s. Aroma compounds were quantified by gas chromatography/mass spectrometry. Volatile compounds were released at significantly different rates. The release of hydrophobic compounds from the oil was decreased, whereas the release of the hydrophilic compound diacetyl was increased in comparison with the water matrix. Interactions were observed between volatile compounds and matrix, as well as between volatile compounds and mastication. Linear release rate constants were related to physico-chemical characteristics, such as molecular weight, boiling points, vapour pressures, octanol-water, gas-water and gas-oil partition coefficients. The octanol-water partition coefficients correlated reasonably well with linear release rate constants for the release from water and oil without mastication, and from water with mastication. The other physico-chemical characteristics correlated poorly with linear release rate constants. (C) 2000 Elsevier Science Ltd. All rights reserved.