Partition coefficients of aroma compounds in polysaccharide solutions by the phase ratio variation method

The partition coefficients (K) of aroma compounds (a homologous series of ketones, hexanal, t–2-hexenal, ethyl butanoate and 1-hexanol) in polysaccharide solutions were determined by the phase ratio variation method (PRV method) using a headspace autosampler. This method enabled easy determination of the partition coefficients of volatile compounds in a gas/liquid system without external or internal calibration, and the results agreed well with published data obtained by direct method. Measurements of K at different temperatures enabled the investigation of aroma compound retention by maltodextrin and β-cyclodextrin during heat treatment. In a maltodextrin solution, retention depended on the hydrophobicity of aroma compounds and it was favoured by the increase of temperature (from 60 to 80 °C). In a β-cyclodextrin solution, temperature variations produced different effects on the retention of aroma compounds and could reveal differences in the nature of the interaction with β-cyclodextrin.