Morphology-regulated stabilization mechanisms of complexes involving nanocellulose and zein nanoparticles in O/W and W/O/W emulsions: Interfacial property and network formation.

This study systematically explored the morphology-regulated stabilization mechanisms of electrostatic complexes involving zein nanoparticles (ZNPs) and millet bran nanocelluloses with different morphologies (cellulose nanocrystals MCNCs, nanofibrils MCNFs, and nanospheres MCNSs) in oil-in-water (O/W) and water-in-oil-in-water (W/O/W) double emulsions. MCNCs-ZNPs exhibited a uniform microstructure, the highest surface charge density (-35.90 mV), and rapid interfacial adsorption, resulting in superior dispersion and stability of emulsion droplets. Conversely, MCNFs-ZNPs and MCNSs-ZNPs mainly relied on dense interfacial film formation but exhibited insufficient steric hindrance and weak network formation in the emulsions. These differences resulted in distinct performance in W/O/W double emulsions, where MCNCs-ZNPs achieved the highest encapsulation efficiency (94.65 %) with excellent storage and processing stability, whereas MCNFs-ZNPs and MCNSs-ZNPs showed lower encapsulation efficiencies (93.10 % and 62.91 %) and inferior stability. These findings support a dual stabilization mechanism involving morphology-regulated interfacial properties and network formation, providing a foundation for the design of sustainable, plant-derived emulsifiers.