Preparation and characterization of oil in water in water (O/W/W) emulsions with food applications

Abstract

Food industry is increasingly aware of the importance of maintaining a healthy diet. For this reason, this industry tries to obtain the same products with less fat content. Elaboration of emulsions allows obtaining similar textures to traditional food products, such as sauces. Oil in water emulsions (O/W) are most common in this industry, however, by making multiple emulsions a wide variety of textures can be obtained. In the production process it is possible to choose oily phase proportion, controlling the amount of fats of the final product. The objective of this work is to obtain an oil in water in water emulsion (O/W/W) with a low oil content. For this, firstly, oil in water emulsions have been prepared by emulsifying sunflower oil in casein with different types of agitation until obtaining the desired drop size and stability. A small proportion of oil has been chosen respect to the amount of casein. To ensure enough stability of this emulsion for a period of time, it has been stabilized by the addition of different percentages of surfactant until founding the most suitable concentration. The size distribution of oil droplets of the emulsions and its stability has been determined. Once the O/W emulsion has been characterized, it has been dispersed in alginate by different types of agitation, obtaining a multiple emulsion of oil in water in water (O/W/W). This emulsion has been characterized, determining emulsion drop size and its stability. Subsequently, this multiple emulsion has been gelled with different concentrations of a calcium chloride solution and its rheological behavior has been evaluated and comparing it with a commercial sauce, specifically, mayonnaise. Oil contained amount in resulting emulsion is lower, so it is an interesting proposal for the food industry to achieve obtaining emulsions with industrial sauces texture and less content in oil