The nature and amount of constituents in food greatly influence aroma release. Pectins and carrageenans are common used thickeners, but their effect on the release of aroma compounds has been studied more frequently for non-homogeneous products than for thickeners separately. The purpose of this work was to study and compare their respective effects in simple model systems. In this way, the release of 13 aroma compounds was analysed by headspace analysis at equilibrium in pure water, iota-carrageenan and pectin gels. To evaluate the influence of the chemical structure of aroma compounds on retention/release equilibrium between vapour phase and gels, we used a quantitative structure-activity/structure-property relationships (QSAR/QSPR) approach. Our present aim was first of all to identify some relevant structural properties related to the retention and then to propose a qualitative interpretation. We used the genetic function approximation (GFA) available in the Cerius(2) package to generate (QSAR) equations with one, two and three variables, with or without constant adding. The two variables equations without constant adding obtained involve the descriptors Jurs-PNSA-1 and Jurs-WNSA-2 for retention in water and in carrageenan gel, Jurs-RPSA and CHI-V-3_P for retention in pectin gel. This result highlights that iota-carrageenan does not modify the nature of interactions between aroma and water molecules, but suggests that interactions with pectin are somewhat different, involving positively charged surface areas in the retention phenomenon.