Pickering emulsions synergistically stabilized by cellulose nanocrystals and peanut protein isolate

This study investigated the stability of Pickering emulsions using cellulose nanocrystals (CNCs) and peanut protein isolate (PPI) complexes as emulsifier. CNCs were prepared by cotton linter cellulose using ammonium persulfate oxidation method; the size was determined to be 145.7 ± 2.6 nm with by a dynamic light scattering particle sizer. Transmission electron microscopy showed that CNCs exhibited a needle-like rigid structure. The prepared CNCs were complexed with PPI at pH 3.5, and CNCs/PPI complexes were used as emulsifiers to prepare Pickering emulsions. Stability analysis, including of storage stability and oxidative stability, revealed that Pickering emulsions with CNCs/PPI complexes were much more stable than those of pure CNCs or PPI. Pickering emulsions exhibited good stability with low creaming index after 30 d of storage. Compared with pure rapeseed oil, Pickering emulsions showed good oxidative stability with lower content of primary products (peroxide values, POVs) and secondary products (thiobarbituric acid reactive substances, TBARS) of lipid oxidation following dark auto-oxidation at 37 °C for 14 d. This study demonstrates CNCs/PPI complexes exhibit better emulsifying properties than pure CNCs or PPI. Pickering emulsions stabilized by CNCs/PPI complexes is stable, edible, and surfactant-free, and is expected to have applications in oil-water separation and lipophilic nutrient delivery.