Fabrication and stability of Pickering nanoemulsion stabilized by self-aggregated chitosan nanoparticles

The fabrication of Pickering nanoemulsions, specifically food-grade ones, is challenging due to the limited availability of particles with appropriate amphiphilic wettability and sufficiently small particle size. Chitosan nanoparticles offer a promising solution due to their adjustable size and amphiphilic properties. The study investigated the effects of pH, oil phase volume fraction, chitosan concentration, and ultrasonic intensity on the formation of chitosan Pickering nanoemulsions. Nanoemulsions with droplet size of approximately 300 nm were achieved under optimal conditions of pH 6.5, oil phase volume fraction of 1 %, chitosan concentration of 1.0 wt%, and 455 W ultrasonic power for 360 min. Stability tests indicated that the nanoemulsions had good pH (2-6), ionic strength (100-500 mM), thermal (60-90 °C), freeze-thaw (3 times) and storage stabilities (0-60 days). The findings highlight the potential of chitosan nanoparticles as effective stabilizers for Pickering nanoemulsions, providing valuable insights for the development of food-grade Pickering nanoemulsions.