Emulsions

Understanding the factors affecting emulsion stabilization and pathway of lipid oxidation

Emulsion stability is often referred to as physical stability, i.e., the maintenance of small, individual droplets of liquid evenly dispersed within the continuous phase of another liquid. To maintain small droplets, the interface is often stabilized using amphiphilic molecules or hydrocolloids.

The physical stability is not, however, alone sufficient to provide the required shelf-life for perishable products, such as those containing polyunsaturated fatty acids. Unsaturated fatty acids are recommended in human diet due to their health benefits; however, the presence of double bonds in the fatty acid chain makes them prone to oxidization by a radical chain mechanism. Lipid oxidation is undesirable because it decreases the nutritional value and leads to the development of off-flavors (“rancidity”) and the formation of potentially toxic reaction products. This has restricted the incorporation of polyunsaturated lipids into many food products. O/W emulsions are even more prone to oxidation than bulky oil, due to the high oil surface area available for the reactions with oxygen.

We characterize the potential of hemicelluloses to formulate and maintain small droplets of oil in water and prevent lipid oxidation. Our aim is to understand the pathway and factors affecting the stabilization.