Gerardo Pereira

Viscosities of aqueous solutions of sucrose and sodium chloride of interest in osmotic dehydration processes

Abstract Osmotic dehydration of food involves the utilization of solutions with one or several solutes that increase considerably the viscosity of the liquid phase. As commercial sugar and sodium chloride are the common solutes employed in this type of processes, kinematic viscosities of binary and ternary aqueous solutions of these solutes were measured at various concentrations (from 0 up to 4.5 mol kg −1 at 0.5 mol kg −1 intervals) and temperatures (from 20 up to 50 °C). Additionally, densities of each solution at 25 °C are reported. Experimental data were simultaneously correlated with concentration and temperature for binary and ternary solutions with a satisfactory accuracy.

An Equation for Modelling the Kinematic Viscosities of Binary and Ternary Solutions with Sugars and Sodium Chloride as a Function of Concentration and Temperature Experimental Data of Solutions with Lactose

An equation to model experimental data of kinematic viscosities of aqueous solutions commonly employed in osmotic dehydration is proposed in this article. The binary and ternary systems are constituted by water as solvent and by sugars (sucrose, glucose, and lactose) and glycerol with or without sodium chloride as solutes. Experimental data of kinematic viscosity of aqueous lactose solutions (with and without sodium chloride) are determined in this work. The range of concentration of all systems studied covers the typical experimental conditions of interest (from 0 to 5.0 mol kg−1 for sodium chloride and 0 up to 0.5 mol kg−1 for lactose) in this type of processes and temperature varied from 20 to 50°C. The parameters of the equation proposed for each system were optimized and the resulting expression adjusted experimental data with deviations less than 3.0%.