Cinnamaldehyde release behavior of Pickering emulsion synergistically stabilized by Sapindus mukorossi modified palygorskite and chitosan

Most of the studies are committed to explore the natural green stabilizer or bio-stabilizer to design biocompatible Pickering emulsion, while few works focus on developing a dynamic interfacial regulatory effect for the slow-release of active molecules from Pickering emulsion. Herein, Pickering emulsion was fabricated for the controlled release of cinnamaldehyde, which was synergistically stabilized by palygorskite modified with the active ingredients leached from Sapindus mukorossi and chitosan. The results showed that the interfacial cross-linking between chitosan and cinnamaldehyde took place at the oil-water interface based on the formation of Schiff base, while the modified palygorskite was adsorbed onto the oil-water interface to co-stabilize Pickering emulsion. The simulated gastrointestinal experiment indicated that the emulsion was stable in simulated gastric fluid (SGF) of pH 1.5, and then destroyed in simulated intestinal fluid (SIF) of pH 6.8 to realize the continuous release of cinnamaldehyde, where the amount of chitosan played a vital role. Furthermore, the antibacterial test showed that the growth of Escherichia coli and Staphylococcus aureus was almost completely suppressed when the concentration of Pickering emulsion was 25 µL/mL. Therefore, this study developed a facile strategy to regulate the controlled release of cinnamaldehyde based on green Pickering emulsion.