Analysis of rheological properties of food macromolecules at infinitely diluted and fixed high concentrations in aqueous NaCl solutions

Abstract

The viscometric parameters intrinsic viscosity [η] and apparent viscosity η^a_H, and several derived parameters, were compared for food macromolecules in water and aqueous NaCl solutions. On dilution of the macromolecules, the [η] values of polyelectrolytes were more strongly dependent on the NaCl concentration than were those of non-polyelectrolytes. At a fixed high concentration of macromolecules, the η^a_H of almost all macromolecules was barely affected by NaCl. However, the η^a_Hvalue of xanthan increased with the NaCl concentration. The activation energy of η^a_Hwas lower in xanthan solutions containing various NaCl concentrations, implying that xanthan is thermally stable. Considering other various viscometric parameters, the rheological properties of food macromolecules were classified into four groups, which were partly based on their approximate molecular weights.