PhD defence

Combined physical and oxidative stability of foodPickering emulsions

Summary:

Many food, cosmetic or pharmaceutical products are oil-in-water emulsions, i.e., a dispersion of oil droplets in an aqueous phase. Preventing adverse chemical degradation of such systems is a challenge, and in particular, the oxidation of healthy unsaturated lipids. Lipid oxidation in emulsions is often tentatively prevented by using oil-soluble antioxidants (e.g., tocopherols) which locate inside the oil droplets. However, since lipid oxidation is initiated at the oil-water interface, the antioxidant activity is far from optimal, and could be enhanced by locating them at the interface. In this work, we developed food emulsions with a new and controlled architecture. In these emulsions the oil droplets were covered with food-grade Pickering particles that exerted a double role: they acted as physical stabilizers, and as a reservoir for antioxidant molecules located close to the oil-water interface, therewith preventing the first lipid oxidation events, which drastically enhanced antioxidant activity.