Highly stable solid-like Pickering emulsions stabilized by kafirin-chitosan complex particles

This paper aimed to construct kafirin-chitosan complex particles through the anti-solvent co-precipitation method and explore its potential as a Pickering emulsifier. The results showed that the contact angle of prepared kafirin-chitosan particles was close to 90° and the zeta potential exceeded 50 mV at the mass ratio of 8:1. The highly charged kafirin-chitosan particles with good wettability could effectively adsorb at the oil/water interface. The droplet size of the Pickering emulsion decreased with the increase of kafirin-chitosan particle concentration. When the particle concentration was 2.0 wt% and the oil fraction was 70%, the droplet size of the Pickering emulsion was about 12.4 ± 0.8 μm. Such a small droplet size could increase the droplet-droplet interaction, thus endowing Pickering emulsion with good viscoelasticity. The microstructures indicated that the kafirin-chitosan particles thoroughly covered the polygonal oil droplets, which was conducive to improving the interface film strength of the Pickering emulsion. Consequently, the prepared Pickering emulsion had excellent rheological properties and anti-coalescence stability. The Pickering emulsion at low pH and ionic strength had good stability after 42 days of storage. Therefore, this present research provided a practical strategy to fabricate edible Pickering emulsions with good texture and stability.