Volumetric and UV absorption studies on understanding the solvation behavior of polyhydroxy solutes in l-ascorbic acid(aq) solutions at T = (288.15 to 318.15) K

Abstract

Thermodynamic and spectroscopic data characterizing the solvation behavior of polyhydroxy compounds are in demand to get better understanding about the mechanisms of taste chemoreception, protein stabilization, etc. Apparent molar volumes for monosaccharides, disaccharides, derivatives, and polyols in (0.05, 0.15, 0.25 and 0.35)molkg−1 aqueous solutions of l-ascorbic acid have been determined from density data measured at (288.15, 298.15, 308.15 and 318.15)K under atmospheric pressure. Standard partial molar volumes at infinite-dilution and corresponding volumes of transfer of solutes from water to l-ascorbic acid(aq) have been calculated. Interaction coefficients and standard partial molar expansibilities have also been evaluated. The basic taste quality of studied solutes has been assessed from apparent massic volumes. UV absorption studies support the interactions between solutes and l-ascorbic acid. Influence of pH variation was taken into consideration while evaluating chemical behavior and stability of l-ascorbic acid in aqueous and buffer solutions.