Physicochemical study of mixed systems composed by bovine caseinate and the galactomannan from Gleditsia amorphoides

Model systemsformed by sodium caseinate (NaCAS) and espina corona gum (ECG) were studied. Therewas no evidence of attractive interactions between NaCAS and ECG macromolecules.Aqueous mixtures of NaCAS and ECG phase-separate segregatively over a wide rangeof concentrations. According to the images obtained by confocal laser scanning microscopy,NaCAS particles form larger protein aggregates when ECG is present in the system.An increase in the hydrodynamic diameter of NaCAS particles, as a result of ECGaddition, was also observed by light scattering in diluted systems.A depletion?flocculation phenomenon, in which ECG is excluded from NaCAS surface,is proposed to occur in the concentrated mixed systems, resulting in NaCAS aggregation.ECG raises the viscosity of NaCAS dispersions without affecting the Newtonian Flowbehaviour of NaCAS. These results contribute to improve the knowledge of a barely-studiedhydrocolloid which may be useful in the development of innovative food systems.