Physicochemical properties and antioxidant potential of phosvitin–resveratrol complexes in emulsion system

• A novel egg yolk phosvitin–resveratrol microemulsion has been produced.
• The physicochemical characterization of the microemulsion has been described.
• A synergistic antioxidant activity was observed in the microemulsion.

Egg yolk phosvitin is the most highly phosphorylated protein found in the nature. The physicochemical properties of phosvitin–resveratrol complexes and their synergistic antioxidant activities in microemulsions were investigated. The particle diameters of microemulsions containing 0.5%, 1.0% and 2.0% phosvitin were 2.660, 0.501 and 0.414 μm, respectively. The emulsifying activity index increased largely from 3.72 to 21.5 m2/g with increasing phosvitin concentration from 0.5% to 2.0%. Fourier transform infrared spectroscopy and thermal analyses indicated that the microemulsions underwent a conformational change during homogenization. Antioxidant assays showed that phosvitin–resveratrol microemulsions exhibited a higher antioxidant activity than that of phosvitin–resveratrol primary emulsions. The MTT assay indicated that HepG2 cell viability remained higher than 80% at phosvitin concentration below 1.0 mg/ml. This suggested that phosvitin, when coupled with polyphenol, can effectively inhibit lipid oxidation in food emulsions, which provided valuable insights into deep processing and application of egg proteins in food industry.