Investigation on Volumetric and Viscometric Properties of Aqueous Solutions of L-Aspartic Acid and L-Glutamic Acid in Presence of Sodium Acetate

Abstract—This investigation is made to predict and assess the interactions of two nonessential amino acids (L-aspartic acid and L-glutamic acid) with a food additive, sodium acetate in aqueous medium. Volumetric and viscometric methods are chosen to determine various physicochemical and thermodynamic parameters important for understanding the interactional behavior of the amino acids with sodium acetate and the effect of these interactions on 3D network structure of water. Analysis of parameters like apparent molar volume, limiting apparent molar volume ($V_{\phi }^{0}$), limiting apparent molar expansibility ($E_{\phi }^{0}$) and viscosity coefficients (${{B}_{{{\text{J\;}}}}}$ and ${{A}_{{\text{F}}}}$) indicates towards $({{V}_{\phi }})$ strong ion-solvent interactions in the experimental solutions. Variations of $E_{\phi }^{0}$ and ${{B}_{{{\text{J\;}}}}}$ with temperature substantiate the kosmotropic character of the amino acids in presence of SA. Evolution of high energy transition state in order to initiate viscous flow of solutions is evidenced by the positive activation enthalpy and free energy of activation of viscous flow.