Transport properties of aqueous solutions of sodium alginate at 298.15 K

Mutual diffusion coefficients (interdiffusion coefficients) of sodium alginate in aqueous dilute solutions, at concentrations from 0.001 to 0.500 g mL−1 and at 298.15 K, alone and in combination with caffeine, using an open-ended conductimetric capillary cell, have been measured. These results are discussed in the light of structural analysis conducted by means of theoretical calculations (molecular mechanics).Based on such results, the equivalent conductance at infinitesimal concentration of the alginate ion in the referred solutions, at 298.15 K, has been estimated. These studies, complemented by some density and viscosity measurements, and carried out at the same range of concentrations, permit us to have a better understanding of the structure of these systems and the thermodynamic behaviour of sodium alginate in different media, that is, improving the know how of the physical and chemical interactions of those two important food chemistry components.

Research highlights
► Mutual diffusion coefficients of sodium alginate in aqueous dilute solutions.
► Complementary rheological and molecular mechanics studies.
► Influence of the presence of caffeine in aqueous media.