Hydroxypropyl chitosan modified by cinnamic acid derivative nanoparticles for stabilising Pickering emulsion

Chitosan (CS) derivatives, chemically modified appropriately, can be used to produce nanoparticles with good properties. In this work, using CS, hydroxypropyl CS (HPCS) and HPCS modified by cinnamic acid (HPCS-CA) derivative as raw materials, the nanoparticles were synthesised by ion crosslinking method with tripolyphosphate. FT-IR spectra indicated that CS and its derivatives successfully cross-linked with TPP at the molecular level. XRD and TG results exhibited changes in crystallinity and thermal stability. The nanoparticles had narrow size distribution and were nearly spherical. The surfaces of the nanoparticles were all positively charged. The nanoparticles-stabilised oil-in-water Pickering emulsions were obtained by high-speed homogenisation. The emulsions' morphology was reported by confocal laser scanning microscopy, indicating that the Pickering emulsions were synthesised successfully. The stability of the emulsion stabilised by HPCS-CA nanoparticles was better than that of CS and HPCS nanoparticles. Taking curcumin as the target component, its stability in Pickering emulsions was good. The Pickering emulsion stabilised by HPCS-CA nanoparticles may be a novel bioactive compound delivery system.