Fabrication of stable Pickering double emulsion with edible chitosan/soy ?-conglycinin complex particles via one-step emulsification strategy

Double emulsion is the most common multiple emulsion with compartmentalized internal structure. It can be used for delivery of both hydrophilic and hydrophobic bioactives and fat reduction in foods. However, con-ventional approach for stable double emulsion preparation often requires high dosage of synthetic surfactants (e. g., polyglycerol polyricinoleate, PGPR) and complicated two-step emulsification process. Herein, we report a facile approach to create stable double emulsion using particular emulsifier of edible chitosan/soy beta-conglycinin (7S) complex nanoparticles via one-step emulsification. By modulating chitosan/7S complex ratio of particles and algal oil content in oil phase, water-in-oil-in-water (W/O/W) Pickering double emulsion was generated in most cases. The dominant mechanism for one-step generation of Pickering double emulsion can be attributed to the polyunsaturated fatty acids (PUFA) in algal oil. The binding of PUFA on particle surface contributes to hydrophobization of the chitosan/7S complex nanoparticles, leading to stabilization of W/O interface. Moreover, stability of the resultant Pickering double emulsions is correlated to particle contact angle. When using nano -particles with chitosan/7S complex ratio of 1:2 and oil phase containing 40 wt% algal oil, particle contact angle at O/W interface is near 90 degrees, which is the optimum condition to produce highly stable Pickering double emulsion. This facile approach for the fabrication of stable double emulsion is promising for a wide range of applications, particularly in food field.

Automated summary

A facile approach to create stable double emulsion using edible chitosan/soy beta-conglycinin (7S) complex nanoparticles as emulsifier via one-step emulsification is reported. The resulting Pickering double emulsion is stable and has potential applications in various fields, especially in the food industry.