Enhancement of catechin loaded in BSA-pullulan nanoparticles on the oxidation stability of pickering emulsion: Effect of concentration

Preventing and delaying the lipid rancidity especial O/W emulsion system is an important task in the food industry. Low solubility in aqueous/lipid phases and poor stability of catechins limited the antioxidant effect in O/W emulsion. To enhance the oxidative stability of O/W emulsions, bovine serum albumin (BSA)-pullulan (PUL) nanoparticles (BPNs) and catechins-loaded BPNs (BPCNs) were successfully fabricated via self-assembly in this paper. Fourier transform infrared (FTIR) spectra of BPNs and BPCNs indicated that self-assembly of BSA and PUL to form nanoparticles and loading of catechins in BPNs are all maintained through non-covalent interactions. Particle size distribution, zeta-potential, structural characterization and interfacial properties of BPNs and BPCNs showed that catechins act as cross-linking “bridge” among BSA molecules, leading to an increase in the mean particle size, surface charges, interfacial properties, radical scavenging activity of BSA-PUL nanoparticles. Compared with BPNs, BPCNs can significantly enhance the storage stability and oxidative stability of Pickering emulsions. In conclusion, enhancement of BPCNs on oxidative stability of the Pickering emulsions not only because of the radical scavenging activity of the loaded catechins, but also attributed to the effect of catechin loading on the increased interfacial charge and balanced the amino acids distribution of BSA in the BPCNs. This study highlights the excellent properties of BSA-pullulan-catechin nanoparticles as novel emulsifiers with high antioxidant activity and potential applications in the food industry. • Loaded catechins in nanoparticles enhance the free radical scavenging activity. • Oxidative and storage stability of BPCNs stabilized emulsions were higher than BPNs. • The enhanced oxidative stability was attributed to the free radical scavenging activity. • Oxidative stability was also enhanced by the increased interfacial charge and balanced amino acid distribution.