Release of limonene from polysaccharide matrices: viscosity and synergy effect

A detailed study of limonene release behaviour from water-based low-concentration polysaccharide solutions and weak gels is reported. On the one hand, rheological measurements made it possible to characterize xanthan (X) and galactomannan [guar gum (G) and carob gum (C)], alone or mixed together. On the other hand, release behaviour of limonene from the previous matrices was quantified using a solid phase micro extraction technique combined with gas chromatography analysis. All of the results indicated large differences in release behaviour, depending on both the matrix composition and the solution viscosity. Moreover, when synergistic interactions between the polysaccharides were developed in the media (X/C mixtures), the results clearly indicated that the release was greatly reduced, thus showing that the volatile release behaviour was not only governed by steric phenomena but also resulted from the occurrence of specific interactions that remain to be elucidated.