effect of composition on release of aroma compounds

the effect of oleic acid (5 and 10% v/v) and xanthan gum (0.5 and 1% wt) on  partitioning and retention of ethyl acetate and diacetyl from two matrices with a different composition was investigated by applying static head space gas chromatography. two matrices with different composition have been developed: one containing carbohydrates (xanthan gum) and in the second one, called complex matrix, lipid (oleic acid) was added. the roles of xanthan gum (xg) and lipid (oleic acid) on the retention of aroma compounds were pointed out. changes in the composition of matrices exhibited a considerable effect on the air/liquid partition coefficient (ka/l ) values at equilibrium. the kinetic study of the release from both matrices had shown a decrease of the initial rate of release (ri) by reference with water. the rheological properties of all matrices were investigated and the flow behavior of all matrices was successfully modeled with power law and cross models. power law model was found as the better model to describe the flow behavior of dispersions.