Characterization of Physical and Oxidative Stabilities of Oil-in-Water Emulsions Stabilized by Flavonoid Glycosides Obtained from Camellia Oleifera Cake and Small-Molecular Surfactants

Abstract

Oil-in-water (O/W) emulsions were co-stabilized by flavonoid glycosides (FG) in Camellia oleifera cake and small-molecular surfactants (SDS/CTAB). FG showed antioxidant capacity, no hemolysis, and emulsifying capacity. The optimum synergy ratio of SDS/CTAB-FG was 0.167/0.091. The physical and oxidative stabilities and action mechanism of FG-surfactants-stabilized emulsions stabilized were investigated. Results showed that the oil-water interfacial tension of FG-surfactants was lower than that of surfactants. After storage, the droplet size distribution of emulsions stabilized by SDS/CTAB-FG was monomodal with a smaller size of 0.262/0.211μm. The presence of FG alleviated the changes of cream volumes and retarded droplet coalescence and Ostwald ripening. Moreover, the addition of FG reduced the lipid hydroperoxides and 2-thiobarbituric acid reactive substances contents of emulsions. FG was more suitable with anionic surfactants to retard lipid oxidation owing to different interaction modes. These findings implied that FG, a natural antioxidant, could enhance the physical and oxidative stability of O/W emulsions.

Keywords: Oil-in-water emulsions, Camellia oleifera cake, Flavonoid glycosides, Small-molecular surfactant, Physical and oxidative stabilities, Interaction modes.