Phase Separation in Gelatin/Maltodextrin and Gelatin/Maltodextrin/Gum Arabic Mixtures Studied Using Small-Angle Light Scattering, Turbidity, and Microscopy

The kinetics of phase separation were observed in the gelatin/maltodextrin and gelatin/maltodextrin/gum arabic systems, where gum arabic was added as a minority component, using small-angle light scattering, turbidity measurement, and confocal scanning laser microscopy. Phase separation occurred by spinodal decomposition for quenches both above and below the temperature at which gelatin gelled. Coarsening of the phase-separated microstructure was hindered by gelation, and a hydrodynamic mechanism, observed when the gelatin remained in the liquid state, was suppressed. Gum arabic, containing both polysaccharide and polypeptide components, was hypothesized to be potentially interfacially active in the gelatin/maltodextrin system, in analogy with synthetic block copolymer compatibilizers in demixed synthetic polymer systems. The hypothesis was experimentally refuted under the chosen experimental conditions, as no evidence was found to suggest that it altered the phase separation behavior.