Fabrication and characterization of antioxidant pickering emulsions stabilized by lysozyme/xanthan gum complex particles

Abstract

A polysaccharide-protein complex can be used as a Pickering particle in a biocompatible Pickering emulsion, improving the emulsion stability by providing high surface activity and viscosity in the colloid system. The aims of this study were to develop biopolymer-based Pickering particles by conjugating the protein, lysozyme (Ly) and the polysaccharide, xanthan gum (XG) and to fabricate an anti-oxidant Pickering emulsion by encapsulating rosemary extract (RO). The Pickering emulsion stabilized by 0.2% Ly/XG particles (Ly/XG NPs) exhibited a creaming index of only 10.46% after 5 weeks and remained the most stable after the addition of several concentrations of NaCl. Additionally, we confirmed the improvement of the emulsifying capacity due to the formation of the Ly/XG complex. To produce an antioxidant Pickering emulsion, RO was encapsulated in Ly/XG Pickering particles. The RO-loaded Ly/XG particles (RO-Ly/XG NPs) sustained its antioxidant activity under UV-A irradiation and exhibited an excellent emulsifying capacity under centrifugation. The Pickering emulsion stabilized by RO-Ly/XG NPs inhibited lipid hydroperoxide production under the 12 hours of UV exposure. We concluded that Pickering particles with excellent antioxidant activity adsorb at the oil/water interface, forming a packed layer and removing free radicals, which results in increased emulsion stability and prevention of lipid oxidation.