Application of Quantitative Structure-Property Relationships (QSPR) approach to aroma release study

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إنجليزي. Up to now, there are few studies related to QSPR (Quantitative Structure-Property Relationships) (Hansch et al., 1964)approach of partitioning coefficients of aroma compounds between vapor phase and food matrices (Carey et al., 2002). We perform a QSPR approach with the aim to evaluate the influence of the chemical structure of aqueous matrices over the partition coefficient between the gas phase and the matrix (Tehrany et al., 2004). Two cases were investigated: (i) -carrageenan gel and (ii) fat-free stirred yogurt containing different concentration of thickeners. The determination of the partition coefficient was performed by headspace analysis at equilibrium. Starting from classical groups of descriptors available in Cerius2 QSAR+ package (Accelrys, Inc.), we selected around 10 descriptors to account for intermolecular interactions. For both saline solution and -carrageenan gel, the descriptors involved in the best obtained equations encode molecules shapes and electronic properties of charges repartition. In this way, key favourable factors for the aroma release in both gel and water are chain branching and molecular negative charge. The effect of carrageenan polymers only modules but does not change interaction of aroma compounds with water molecules. For yogurt, shape and surface descriptors take account of retention related to increasing amount of starch, showing that the increasing molecular volume and polarisability, i.e. van der Walls hydrophobic interactions, improve the retention of aroma molecules. Conversely, retention related to increasing amount of pectin are correlated with charges descriptors, pointing forward the power of dipole-dipole interaction and hydrogen bonding in the retention of aroma by pectin. To conclude, QSAR/QSPR approach allows highlighting the nature of the interactions due to various components of the food matrix and constituting a promising way to better understand the nature of intermolecular interactions involved between macromolecules and aroma compounds.