Effect of Emulsifying Condition on Emulsification with Soybean Lecithin

Abstract

Effects of emulsifying conditions on the stability, droplet size and viscosity of emulsions prepared by using soybean lecithin were investigated. Better stability was obtained from the emulsion emulsified by a syringe rather than by a Hansen High Performance Disperser. Comparing the stability of the emulsions prepared by three dispersing methods with lecithin in water, Hansen dispereser(A), heating(B)and ultrasonication(C), A was the best and C was the worst. Droplet size decreased with an increase of the lecithin amount added. Droplet of the emulsion prepared by dispersing the emulsifier in oil was smaller than that of the emulsion prepared by dispersing the emulsifier in water. The emulsion became unstable as the emulsifying temperature as well as the standing temperature after emulsification was elevated. Viscosity of the emulsion increased with an increase of the lecithin content and the viscosity of the sample prepared by dispersing lecithin in oil was higher than that of the sample prepared by dispersing lecithin in water. The viscosity of the emulsion decreased with an elevation of standing temperature, and the viscosity behavior depended upon emulsifying method and lecithin content. These results indicate that the emulsion comprised of smaller droplet shows good stability and high viscosity.