Effect of aqueous phase composition on particle size and stability of sunflower oil/sodium caseinate nanoemulsions

JUAN MANUEL MONTES DE OCA AVALOS; ROBERTO J CANDAL; MARIA LIDIA HERRERA

Orlando

Congreso; 106th AOCS Annual Meeting and Industry Showcases; 2015

American Oil Chemists' Society

Many nanoemulsions are currently formulated with synthetic surfactants. The objective of the present work was to prepare transparent nanoemulsions using a natural emulsifier. Nanoemulsions were prepared by using the evaporative ripening method. In this method, a volatile organic compound (such as ethyl acetate) was removed from the sample by a thermal process at low pressure which produces a droplet shrinkage down to nanometer sizes. Maintaining fix concentrations of 1.64 wt.% sunflower oil and 0.98 wt.% sodium caseinate, several concentrations of sucrose or trehalose were added to the system: 0, 2, 4, 6, 8, 10% w/w. Analysis were performed by dynamic light scattering techniques, determining the size distribution and the zeta potential of the samples. Results show that using the evaporative method, stable monodispersed nanoemulsions were obtained with a mean diameter between 100-200 nm and a narrow distribution. If ethyl acetate was not added to the sample, conventional emulsions in the range of micrometers were obtained with a polidispersed distribution. Moreover, increasing the disaccharide concentration, narrower size distributions were obtained and micrometer droplet sizes, which appeared in a very small amount for low disaccharide concentrations, disappeared.