Surface modification of cellulose nanofibrils with protein nanoparticles for enhancing the stabilization of O/W pickering emulsions

In order to enhance the surface hydrophobicity and emulsifying capacity of cellulose nanofibrils, a 'green' surface-modification with protein nanoparticles was conducted. The adsorption of soy protein isolate (SPI) nanoparticles on the bacterial cellulose oxidized by 2,2,6,6-tetramethylpiperidine-nitrogen-oxide (TEMPO) through electrostatic attraction at pH 3 was investigated. The experimental results demonstrated that the modification increased the surface hydrophobicity of TEMPO-oxidized bacterial cellulose (TOBC), and the complexes expressed the improved interfacial rheological properties. Accordingly, with the increasing contents of complexes, the Pickering emulsions exhibited the smaller droplets size, higher viscosity, and better physical stability. Moreover, the emulsions showed good anti-oxidative stability, where both primary (POVs) and secondary (TBARS) products of lipid oxidation were significantly lower than those of oil without coverage. The results of in vitro digestion indicated the improved anti-lipid hydrolysis performance of emulsions with tunable interfacial structure formed by complexes.