Temperature effect on solubility of aroma compounds in various aqueous solutions

Solubility of nine aroma compounds (methyl ketones, ethyl esters, aldehyde and alcohol) in various aqueous solutions was measured by the mutual solubility method from -10 to +10degreesC. Influence of both, the nature (carbohydrates and polyols) and the substrate concentration (from 0 to 57.5g/100g) on aroma solubility in aqueous solutions was studied. Aroma solubility in water decreased when aroma hydrophobicity increased. Aroma solubility in various aqueous solutions decreased when substrate concentration increased; their solubility was higher in polyols solutions than in polysaccharides ones. Temperature effect on aroma solubility showed a noncontinuous evolution for solutions without ice: from +25 to +4degreesC, solubility decreased, then from +4 to -5degreesC, solubility increased. Finally, from -5 to -10degreesC solubility decreased once again. The same behavior was observed for all studied media. Comparison with other characteristics (such as density and water structure) of the aqueous solutions was done in order to better understand this temperature effect on aroma solubility. (C) 2004 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.