Effect of formulation on structure-function relationships of concentrated emulsions: Rheological, tribological, and microstructural characterization

Since concentrated emulsions are the basis for many commercial products, conducting comprehensive studies on structureefunction relationships of emulsion systems is necessary for targeted product design. Hence, the objectives of this study were to 1) characterize the effects of fish gelatin concentration and oil phase volume fraction on the rheological, tribological and microstructural properties of concentrated emulsions and 2) determine structureefunction relationships based on the measured parameters. Emulsions were prepared using different amounts of oil and fish gelatin, and characterized by rheometry and microscopy. Emulsions containing higher oil or fish gelatin concentrations had greater stability to creaming, larger critical strains, and lower friction profiles. However, they exhibited increased nonlinear behavior under large amplitude oscillatory shear. These results were ascribed to increased homogeneity, higher network extension, and smaller oil droplets in emulsions with higher protein or oil concentrations. These results can be used to incorporate concentrated emulsions in emulsion-based formulations. (C) 2017 Elsevier Ltd. All rights reserved.