A stable peony seed oil emulsion that enhances the stability, antioxidant activity, and bioaccessibility of curcumin

Abstract

In this study, a peony seed oil (PSO) emulsion system, which was stabilized using egg yolk powder-pullulan complex particles (EPCPs), was prepared with an oil-phase mass fraction varying from 10% to 80%. The stability of the emulsions and their potential as carriers for curcumin were investigated. There was no phase separation or oiling off of samples at oil-phase mass fractions from 10% to 80%. Analysis of the average droplet size and microstructure showed that the diameter of the droplets increased as PSO was added. All the emulsions were stable under the environmental conditions tested (storage time, pH, salt, and temperature). The oxidation stability of PSO in the emulsion was higher than that of the oil alone, demonstrating the protective effects of the emulsion. Additionally, the emulsion (φ = 50 g/100 g, blank-emulsion) could effectively encapsulate curcumin, forming a curcumin-loaded emulsion (C-emulsion). The stability and bioaccessibility of curcumin in the C-emulsion were higher than in PSO, and the antioxidant activity of the C-emulsion was also higher than that of the single samples. These findings provide insights into the stability of emulsions with a range of oil-phase mass fractions and the potential of emulsions as carriers of bioactive substances.