Inhibition of Ostwald Ripening in Model Beverage Emulsions by Addition of Poorly Water Soluble Triglyceride Oils

Beverage emulsions containing flavor oils that have a relatively high water-solubility are unstable to droplet growth due to Ostwald ripening. The aim of this study was to improve the stability of model beverage emulsions to this kind of droplet growth by incorporating poorly water-soluble triglyceride oils. High pressure homogenization was used to prepare a series of 5 wt% oil-in-water emulsions stabilized by modified starch that had different lipid phase compositions (orange oil : corn oil). Emulsions prepared using only orange oil as the lipid phase were highly unstable to droplet growth during storage, which was attributed to Ostwald ripening resulting from the relatively high water-solubility of orange oil. Droplet growth could be effectively inhibited by incorporating = 10% corn oil into the lipid phase prior to homogenization. In addition, creaming was also retarded because the lipid phase density was closer to that of the aqueous phase density. These results illustrate a simple method of improving the physical stability of orange oil emulsions for utilization in the food, beverage, and fragrance industries.