Volumetric, UV-Visible, and computational analysis of molecular interactions between L-ascorbic acid and L-histidine in aqueous solutions

In this work, we have performed the physiochemical, spectroscopic, and computational analysis of L-ascorbic acid (AA) in aqueous solutions of L-histidine (L-His). The physicochemical properties were evaluated by measuring density and speed of sound of AA in (0.01, 0.04, 0.08, and 0.12) mol.kg(-1) aqueous L-His at temperatures (298.15 to 313.15) K. UV-Visible absorbance of AA was recorded by varying the concentration of L-His and the electrostatic interactions among these components were also evaluated by molecular dynamics. Derived thermodynamic parameters such as apparent molar volumes (V-2 phi), apparent molar isentropic compressibilities (K-s,K-2,K-phi), partial molar volumes and partial molar compressibilities at infinite dilution (V-2 degrees and K degrees(s,2)), Helper's constants were calculated from density and speed of sound data. The experimental and computational results indicate the presence of strong hydrophilic-ionic types of interactions between AA and L-His in aqueous solutions. Studies of these interactions can help in understanding solvation behaviour of ascorbic acid, which is responsible for food flavoring and aroma owing to formation of Maillard reaction products. (c) 2022 Elsevier B.V. All rights reserved.