Pectin and carrageenan are common used thickeners in fat free foods. The aim of this work was to study separately and to compare their respective effects on the aroma release, in order to investigate the nature of involved interactions. In this way, we studied the influence of the chemical structure of 13 aroma compounds on retention/release equilibrium between vapour phase and gels using QSPR tools. Six descriptors are involved in the best obtained QSPR equations, and three of them appeared to play a critical role in the behaviour of aroma compound. Our results put forward the role of polar effects on the retention of odorant molecules in both iota-carrageenan and pectin gels, indicating that iota-carrageenan polymer do not change the interaction between aroma compounds and water molecules, whereas pectin causes slightly different interaction involving positive charged surfaces areas in the retention phenomenon.