Physical Stability of Beverage Emulsions as Influences of Orange Oil, Tragacanth and Arabic Gums Concentrations

The objective of this study was to examine the influence of tragacanth gum concentrations on physical and mechanical properties of beverage emulsions formulated with arabic gum and orange oil. Beverage emulsions are oil-in-water emulsions and used to enhance juice-like appearance, to provide flavor and deliver functional ingredients (omega-3 fatty acids) to the beverages. Stability of beverage emulsions, in concentrated and diluted forms, is a chronic problem that plagues the flavor and beverage industries and is highly affected by certain physicochemical characteristics of polymeric emulsifiers (hydrocolloids gums) added into the water phase. The emulsions were prepared by adding 18-30% oil phase into hydrated arabic gum (6-12%), followed by addition of hydrated tragacanth gum (0.3-0.8%). The particle size distributions and zeta potential, surface tension, rheological properties and opacity stability of emulsions were characterized. Arabic gum decreased the surface tension between water and oil and therefore boosted up the stability of emulsions. Addition of oil was readily responsible for increasing the opacity of the emulsions. Rheological properties were affected by changing the concentration of main components. All the emulsions show the flow behavior index less than 1 which means they posed shear-thinning behavior.