High fat (>50%) oil-in-water emulsions as omega-3 delivery systems

High fat oil-in-water emulsions are used as delivery systems for fat-soluble bioactive compounds. Oil content in these systems varies substantially and can range from 50 to 80 wt%. High fat oil-in-water emulsions, due their higher volume fraction of dispersed phase, present special challenges in terms of physical and oxidative stability when compared to low fat oil-in-water emulsions. Particularly, the more pronounced packing of oil droplets in high fat oil-in-water emulsions affects its rheology and texture, as well as propagation of lipid oxidation, which will have an influence on their use as omega-3 delivery systems. This chapter discusses the main factors affecting physical and oxidative stability of high fat oil-in-water emulsions such oil content, emulsifier content and type, homogenization method, and addition of antioxidants. Moreover, the presence of metal ions in the ingredients used for production of the emulsion and/or in the food matrix and the pH of both the delivery emulsion and the enriched food system are also addressed as factors affecting the stability of high fat omega-3 delivery oil-in-water emulsions and final enriched food products.