Fabrication and characterization of novel β-sitosterol-loaded O/W Pickering emulsions stabilized by edible insects protein/chitosan complex coacervates: Retention and stability evaluation

This study investigates the application of edible insect protein–chitosan (IP/CS) complex coacervates, derived from T. molitor, A. domesticus, and L. migratoria proteins combined with low-, medium-, or high-molecular- weight chitosans, as stabilizers in Pickering emulsions aimed at enhancing emulsion stability and improving the retention of bioactive compounds. The underlying hypothesis posits that IP/CS can function as effective stabilizing systems in Pickering emulsions, providing high overall stability, low susceptibility to destabilization, and efficient encapsulation of lipophilic bioactives. Experimental results showed that IP/CS-based Pickering emulsions achieved high β-sitosterol retention, ranging from 56 % to 91 %. Emulsion stability was primarily attributed to electrostatic interactions and hydrogen bonding within the coacervates. In addition, an effective stabilization mechanism was identified, involving the physical integration of oil droplets into the IP/CS matrix, which contributed to reduced flocculation. Fourier-transform infrared (FTIR) spectroscopy and rheological analysis confirmed the presence of hydrogen bonding and indicated a viscous character of the emulsions, while ζ-potential measurements revealed surface charge properties that further supported emulsion stabilization. These findings demonstrate the role of intermolecular interactions in maintaining the integrity of oil-in-water (O/W) Pickering emulsions stabilized by IP/CS complexes.