EFFECT OF TWO-FLUID NOZZLES ON THE STABILITY CHARACTERISTICS OF EMULSIONS PREPARED BY A HIGH-ENERGY METHOD (MICROFLUIDIZATION)

The atomization of oil in water emulsions is used in the food industry in the preparation of several products. Its passage through the atomization devices could have an influence on the stability of the emulsion and, consequently on the final product. In the present work, it was evaluated the influence of two fluid nozzles of different dimensions and geometry on stability parameters of oil in water emulsion produced by microfluidization and by using gum Arabic as wall material. Results indicated that the droplet size, the polydispersity index and the Turbiscan stability index of atomized emulsions were affected by an initial destabilization which caused their increment with time. It was found that, atomized emulsions presented Oswald ripening rates more pronounced than original emulsion which possibly included diffusion-interfacial tension compensation. The confocal laser scanning microscopy images confirmed that the passage of the emulsion through the atomization devices decreased the thickness of wall material of the droplets with respect to the original emulsion which strongly influenced the destabilization of emulsions due to decreased coverage and polar-non-polar disruption. It was concluded that, in the design of products prepared by atomization, the stability of the atomized emulsions must be considered by including a proper selection of the atomizer and possibly, a suitable liquid sampling-characterization on-line scheme.