The Impact of the Interfacial Behaviour on Emulsion Rheology: A Potential Approach to Reducing Fat Content in Emulsified Foods

Despite increased awareness of a healthy diet and lifestyle, the number patients in the UK diagnosed with obesity is increasing year on year. To satisfy consumer desires for taste and quality, but in healthier, reduced energy form, a wide range of reduced calorie foods have been developed over many years. Reduced fat versions of many emulsified foods such as dairy products, dressings, sauces and ice creams are often perceived as poorer quality because the perception of fat in food is a complex mixture of sensory, physical and psychological factors. Fat content and oil droplet size both have an effect on perceived creaminess of foods; a higher fat content and smaller oil droplets both give a perception of increased creaminess. If the rheological behaviour of emulsions can be optimised by rational design of the colloidal interactions between the emulsion droplets, it may be possible to improve the overall sensorial qualities of reduced fat foods and hence the uptake of these products. The aim of this study was to determine the extent of the interfacial structure on the rheology of more realistic emulsions, specifically at lower phase volumes in the presence of a stabilising polymer network.