Dielectric relaxation and molecular interactions study of saccharides in aqueous solutions

Time domain reflectometry (TDR) technique has been extensively used to study dielectric relaxation and solution properties of carbohydrates. Using TDR techninque, complex permittivity spectra of monosaccharides (d-fructose and d-xylose) and disaccharides (d-maltose monohydrates) were obtained in the frequency range of 10 MHz-50 GHz at various concentrations and temperatures. The static dielectric constant (ε₀), dielectric constant at high frequency (ε_∞), relaxation time (τ) and relaxation time distribution parameter (β) extracted from the complex permittivity spectra using least squares fit method. The values of static dielectric constant were also verified by LCR meter by dielectric measurement in the frequency range of 20Hz to 2 MHz at 25 °C. The relaxation behavior of aqueous solutions of monosaccharides and disaccharides has been illustrated by using Cole-Davidson model. Activation enthalpy (ΔH), entropy (ΔS) and Kirkwood correlation factor have been determined to study extent of hydrogen bonding. This data might be useful in pharmaceutical, food processing industry and in solubility prediction method in aqueous solution.