Fabrication and characterization of oil-in-water emulsions stabilized by whey protein isolate/phloridzin/sodium alginate ternary complex

Whey protein isolate (WPI) is an important food supplement and natural surfactant. Emulsion systems based on WPI and WPI–polyphenol complex have been the focus of food delivery research. However, these emulsions are pH-sensitive, which limits their application. In this study, an emulsion stabilized by the WPI–phloridzin (PHL)–sodium alginate (SA) ternary complex was constructed for the first time, and its physicochemical properties were characterized. The results indicated that at pH 5.0, the ternary complex possessed higher stability than the WPI–PHL complex. Moreover, the ternary complex significantly enhanced the ABTS radical scavenging ability of PHL at pH 5.0. The emulsion stability increased with increasing SA proportion in the complex. The antioxidant activity and β-carotene retention capacity of the emulsion were also positively correlated with SA concentration. The results suggest that the emulsion stabilized by the WPI–PHL–SA ternary complex is a promising food delivery system.