Effect of protic ionic liquid on the volumetric properties and taste behaviour of sucrose

Volumetric and taste behavior of D(+)-glucose and D(-)-fructose in aqueous solutions of ethanolammoium acetate

The hydration and taste behaviour of glucose and fructose in aqueous ethanolammonium acetate solutions were investigated by measuring volumetric properties. Density and speed of sound were measured at four different temperatures. Apparent and partial molar volumes, apparent specific compressibility, apparent specific volume, transfer volumes, and hydration numbers were determined from the measured density and speed of sound data. Positive transfer properties of saccharides from water to aqueous ethanolammonium acetate solutions suggested the dominance of hydrophilic-ionic interactions. However, such interactions weakened with incremental concentrations of ethanolammonium acetate. The transfer properties increased in the order: glucose > fructose, indicating stronger interactions between glucose and ethanolammonium acetate. The apparent specific volume and apparent specific isentropic compressibility values for monosaccharides in water and in aqueous ethanolammonium acetate were found to fall within the sweet taste modality.

Interactions in saccharide/cation/water systems: Insights from density functional theory

Interactions between saccharides and ions in aqueous solutions are of great importance in many fields (chemistry, physico-chemistry, biology, food industries). Thus, this work proposes to develop a methodology dealing with the characterization and the understanding of interactions between saccharides and cations in presence of water molecules, by a quantum mechanics approach. In the first part, the saccharide hydration properties (xylose, glucose, sucrose) in pure water are determined. Results show that the saccharide coordination numbers, as well as the saccharides hydration enthalpy, increase with the saccharide hydrophilic group number. In the second part, the influence of cations on saccharides hydration properties, and inversely, is evaluated. In saccharide/cation/water systems, the decrease in hydration enthalpy of cations and saccharides shows that both species are dehydrated and that saccharide dehydration depends on the nature of the cation. The dehydration sequence of saccharides was explained from the study of saccharide/cation interactions.

Thermophysical and rheological properties of sorbitol + ([mmim](MeO)2PO2) ionic liquid solutions: Solubility, density and viscosity

In this study, the solubility, density and viscosity of sorbitol as a sugar alcohol in the ([mmim](MeO)₂PO₂) ionic liquid (IL) were measured. The results indicated that sorbitol is highly soluble in this IL. The Flory-Huggins model with an average value for the χ parameter was successfully applied to predict the solubility of sorbitol in IL. The thermodynamic properties such as enthalpy, entropy and Gibbs free energy of dissolution were obtained using experimental solubility data, which demonstrated that the dissolution process is endothermic and non-spontaneous and includes an entropy increase. In addition, the apparent molar volume, apparent molar expansion and thermal expansion coefficient were calculated. The study of the rheological behavior revealed that the sorbitol/IL solution is Newtonian and the Arrhenius, Litovitz, Orrick-Erbar-Type and Vogel-Fulcher-Tamman models were used to correlate the viscosity data.

The sweetness response and thermophysical properties of glucose and fructose in the aqueous solution of some deep eutectic solvents at T= (288.15-318.15) K

Thermophysical properties elucidate the sweetness response, taste quality and hydration characteristics of saccharides in the aqueous solutions and offer significant information for pharmaceutical and food industries. In this current work, the effect of some neoteric green solvents as named deep eutectic solvents (DESs) on the sweetness response, taste quality and hydration behavior of the glucose and fructose solutions have been investigated from apparent specific volumes ASV, apparent specific isentropic compressibility ASIC parameters. The standard partial molar volumes V_φ⁰, transfer apparent molar volumes Δ_trV_φ⁰, partial molar isentropic compressibilities K_φ⁰, viscosity B-coefficients and molar refractions R_D the aqueous solutions of saccharides in choline chloride (ChCl)-urea, ChCl-ethylene glycol (EG), dimethyl ammonium chloride (DMAC)-ethylene glycol as DESs have been calculated from measured density, speed of sound, viscosity and refractive index data at T= (288.15-318.15) K. The results indicated that glucose in the aqueous solutions of ChCl-urea has the strongest interactions and get stronger with increasing the concentration of DES and temperature. Interaction volume V_int and cavity volume V_cav have been computed from scaled particle theory (SPT).

Effect of ionic liquids 1-octyl-3-methyl imidazolium bromide or 1-octyl-3-methyl imidazolium chloride on thermophysical properties and taste behavior of sucrose in aqueous media at different temperatures: Volumetric, compressibility and viscometric properties

The thermophysical properties and taste behavior of sucrose in aqueous ionic liquids {1-octyl-3-methyl imidazolium bromide and 1-octyl-3-methyl imidazolium chloride} solutions have been studied via volumetric, compressibility and viscometric properties at T = (288.15, 298.15, 308.15 and 318.15) K. The positive values of transfer volume and transfer partial molar isentropic compression indicated predominance of ionic-hydrophilic interactions in these systems. The calculated hydration number for sucrose demonstrated that dehydration of sucrose occurs in presence of both studied ionic liquids. Further, the effect of studied ionic liquids on the taste behaviour of sucrose has been discussed from ASV and ASIC parameters. Furthermore, interaction volume, V_int, and cavity volume, V_cav, have been computed from scaled particle theory (SPT).

Role of the triple solute/ion/water interactions on the saccharide hydration: A volumetric approach

The aim of this study is to further the understanding of the mechanisms that govern the hydration behavior of neutral solutes, with respect to the ions' properties that are present in a solution. For that, a systematic volumetric study of saccharides (xylose, glucose and sucrose), in the presence of various electrolytes (LiCl, NaCl, KCl, Na₂SO₄, K₂SO₄, CaCl₂, MgCl₂, MgSO₄) has been carried out with density measurements at 298.15 K. From this data, the standard transfer molar volume of the saccharide ΔV_ϕ,S⁰, which characterizes the hydration state of the solute, has been determined. Positive and increasing values of ΔV_ϕ,S⁰ with increasing electrolyte concentrations were obtained. This indicated the dehydration of the saccharide in the presence of the electrolyte, due to the predominance of saccharide/cation interactions. Concerning the influence of the cation, it was shown that saccharides are more dehydrated in the presence of divalent cations than in the presence of monovalent ones. This is because the interactions are stronger between saccharides and divalent cations, in comparison to those with monovalent cations. For a specific cation valence and molality, regardless of the anion, saccharide dehydration increases according to the following sequences: Li⁺< Na⁺< K⁺ and Mg²⁺< Ca²⁺. These saccharide dehydration sequences have been explained by the Gibbs free energy of hydration of the cations, reflecting the cation/water interactions. For a specific cation valence, it was concluded that decreasing cation/water interactions induce the increase of saccharide dehydration. Concerning the influence of the anion, it was also observed that saccharides are more dehydrated in the presence of divalent anions than in the presence of monovalent ones. It was stated that saccharide/cation interactions are modulated by the nature of the anion. The anion impact was again attributed to its capacity to interact with water molecules. It was pointed out that anions with increasing values of Gibbs free energy of hydration cause an increase in saccharide/cation interactions or a decrease in saccharide/anion interactions. Therefore, saccharide dehydration increases.

Elucidation of molecular interactions between a DBU based protic ionic liquid and organic solvents: thermophysical and computational studies

Energy profile of 1,8-diazabicyclo[5.4.0]undec-7-en-8-ium trifluoroacetate [DBUTFA].

Thermodynamic and ultrasonic properties of ascorbic Acid in aqueous protic ionic liquid solutions

In this work, we report the thermodynamic and ultrasonic properties of ascorbic acid (vitamin C) in water and in presence of newly synthesized ammonium based protic ionic liquid (diethylethanolammonium propionate) as a function of concentration and temperature. Apparent molar volume and apparent molar isentropic compression, which characterize the solvation state of ascorbic acid (AA) in presence of protic ionic liquid (PIL) has been determined from precise density and speed of sound measurements at temperatures (293.15 to 328.15) K with 5 K interval. The strength of molecular interactions prevailing in ternary solutions has been discussed on the basis of infinite dilution partial molar volume and partial molar isentropic compression, corresponding volume of transfer and interaction coefficients. Result has been discussed in terms of solute-solute and solute-solvent interactions occurring between ascorbic acid and PIL in ternary solutions (AA + water + PIL).