Fabrication of Antioxidant Pickering Emulsion Based on Resveratrol-Grafted Zein Conjugates: Enhancing the Physical and Oxidative Stability

Lipid oxidation is still a major problem complicating the development of food emulsions. In this study, an antioxidant Pickering emulsion stabilized by resveratrol-grafted zein (Z-R) conjugates and pectin (P) complex particles was prepared. The hydrophilic pectin successfully adjusted the wettability of Z-R; when the mass ratio of Z-R to P was 2:1 (Z-R/P-2:1), the three-phase contact angle was 90.68 degrees, and the wettability of the particles was close to neutral. Rheological analysis showed that the emulsion formed an elastic gel structure. FTIR spectra indicated that there was a hydrogen bond and electrostatic interaction between Z-R and P. The disappearance of characteristic infrared peaks of corn oil was due to a dense protective film formed on the surface of oil drops by Z-R/P-2:1 particles, which was confirmed by confocal laser scanning microscopy. The emulsion stabilized by Z-R/P-2:1 had excellent physical stability at a wide range of pH values (4-9), salt ion concentrations (0.04-0.15 mol center dot L-1) and storage times (0-30 days). The anti-lipid oxidation ability of the emulsion was outstanding; after storage for 14 days at room temperature, the MDA content in the emulsion was only 123.85 mu mol/kg oil. In conclusion, the Z-R/P-2:1 particles prepared in this study can effectively stabilize a Pickering emulsion and expand the usability of the method for constructing antioxidant Pickering emulsions.

Automated summary

In this study, an antioxidant Pickering emulsion stabilized by zein-grafted resveratrol and pectin complex particles was prepared. The emulsion showed excellent physical stability and outstanding ability to prevent lipid oxidation. Adjusting the wettability of the particles and forming a protective film on the surface of oil droplets contributed to the stability of the emulsion.