Influence of Xanthan, Emulsification Temperature, and Environmental Stresses on the Preparation of Water-in-Corn Oil Emulsions Droplets Coated by Polyglycerol Polyricinoleate

The purpose of this study was to prepare stable water-in-corn oil (W/O) emulsion droplets coated by polyglycerol polyricinoleate (PGPR). W/O emulsions (20 wt% aqueous phase, 80 wt% oil phase containing 8 wt% PGPR) were produced by high pressure homogenization (Emulsions 1), however, appreciable amount of relatively large water droplets (d>$10{\mu}m$) were found. To facilitate droplet disruption, viscosity of each phase was adjusted: (i) increased the viscosity of aqueous phase by adding 0.1 wt% xanthan (Emulsions 2); (ii) decreased the viscosity of oil phase and aqueous phase by heating them separately at $50^{\circ}C$ for 1 hr immediately before emulsification (Emulsions 3). Homogenizing at the elevated temperature clearly led to a smaller water droplet size, whereas xanthan neither improved nor adversely affected on the microstructures of the emulsions. In addition, the Emulsions 3 had good stability to droplet aggregation under shearing stress, thermal processing, and long term storage.