39F-6

A. R. TAHERIAN¹, P. Fustier, and M. Marcotte. (1) Food Research and Development Center, Agriculture and Agri-food Canada, 3600 casavant Blvd West, Saint-Hyacinthe, Quebec, Canada, QC J2S 8E3, Canada

Beverage emulsions are a unique class of emulsions in that they are to be consumed in highly diluted forms. The stability of these emulsions depends upon the density of water and oil phases, the radius of dispersed oil droplets and the viscosity. Properties are obtained from different formulations allow to understand the emulsions system and select the most suitable one. The aim of this study was to investigate the properties associated with different concentrations of gum and oil and their contribution on the stability and the opacity of beverage emulsions. Oil-in-water emulsions were prepared at both constant level of coconut oil (3.72%) and five different concentration of modified starch (3 to 20%), and constant level of modified starch (12%) and five different oil concentrations (3 to 20%). Each sample was homogenized for 3 min using laboratory scale homogenizer (Polytron). Prepared samples were subjected to the following tests: density, creaming and sedimentation, particle size and distribution, zeta potential, viscosity and flow behavior, conductivity, stability in diluted form and the opacity. Results indicated that the gum concentration not only played a big role in the rheological behavior of emulsion but contributed to the density and enhanced the sedimentation if there is not a careful adjustment between the viscosity of the aqueous and density of the dispersed phases. The gum concentration affected both the opacity and the viscosity of formulated emulsions. The oil concentration, on the other hand, had a greater effect (more than 4 times) on the opacity of the emulsion. Both water phase and emulsion showed a dilatant rheological behavior and emulsions with more than 12% starch concentration indicated the presence of the yield stress. Obtained results can be used to select the proper amount of starch and oil to obtain the desirable opacity and stability in beverage emulsions.