Effect of 2-hydroxyethylammonium acetate based protic ionic liquids on thermophysical properties and taste behavior of D-fructose in aqueous solutions at different temperatures

This study reports the density, viscosity, and refractive index data of aqueous solutions of D-fructose in protic ionic liquids (PILs): (2-hydroxyethyl) ammonium acetate [2-HEA]Ac, bis (2-hydroxyethyl) ammonium acetate [bis-2-HEA]Ac, and tris (2-hydroxyethyl) ammonium acetate [tris-2-HEA]Ac at temperature range of (298.15 to 318.15) K. The density data were utilized to calculate the apparent molar volume ( V_φ ) and standard partial molar expansibility ( Eφ⁰ ). Also, the calculated standard partial molar volumes were used to study solute-solvent interactions. The results indicate stronger interactions between [2-HEA]Ac and D-fructose in water which was found to be 118.443 m3·mol−1, compared to the other protic ionic liquids. Additionally, the viscosity B-coefficient was derived using the Jones-Dole equation. The molar refraction ( RM ) was calculated via the Lorentz–Lorenz equation, while COSMO analysis revealed that [2-HEA]Ac exhibits the most substantial interaction with D-fructose among the studied systems. The volumetric properties are also applied in the taste behavior of solutions, where changes in hydrogen bonding and solute-solvent interactions influence the perceived sweetness intensity of D-fructose.