Abstract:Shellac was used to physically modify the structure and improve the emulsifying property of oat protein.The oat protein-shellac nanoparticles prepared at different mass ratios（1∶1，2∶1，and 4∶1）of were prepared and used to stabilize the Pickering emulsion.The particle size，potential，and interfacial wettability of the oat protein-shellac nanoparticles with different mass ratios were measured.The physical stability and rheological properties of the Pickering emulsion stabilized by nanoparticles were determined，on the basis of which the emulsifying properties of oat protein-shellac nanoparticles with different mass ratios were explored.The results showed that with the increase in the mass ratio of oat protein to shellac，the particle size of oat protein-shellac nanoparticles first decreased and then increased and reached the minimum of 289.0 nm when the mass ratio was 2 ∶1.The Ca2+ cross-linking between oat protein and shellac reduced the negative charge on the surface of nanoparticles，and the mass ratio had no significant effect on the surface charge of nanoparticles.The interfacial wettability of oat protein-shellac nanoparticles was negatively correlated with shellac content，and the contact angles of the nanoparticles reached 69.5°and 71.4°at the mass ratios of 2∶1 and 4∶1，respectively.The stability and rheological properties of oat protein-shellac nanoparticle-stabilized emulsion were higher than those of the emulsion stabilized by oat protein.The nanoparticles prepared with a mass ratio of 2∶1 could be irreversibly adsorbed on the oil-water interface due to their small particle size and good interfacial wettability，forming a dense and stable gel network between droplets，which increased the physical stability of the stabilized emulsion by 81.3%.