Abstract: The encapsulation of curcum in kafirin microparticles by anti-solvent method was investigated in this study, and the physicochemical properties and stability of the microparticles were characterized. The results showed that the optimal curcumin/kafirin ratio (m/m) ratio was 1:10. The average particle size and zeta potential of the microparticles obtained under this condition were respectively 13.17 μm and 19.38 mV; the production yield was 87.51%, the entrapment efficiency was 62.61%, and the loading efficiency was 6.51%. Scanning electron microscopy (SEM) showed that kafirin microparticles encapsulating curcum were uniform spheres with a porous surface. Fourier-transform infrared spectroscopy (FTIR) analysis indicated that the peaks at 1 534 and 1 655 cm-1 red shifted; furthermore, the alpha helix and beta-sheet content were respectively reduced and increased. The stability of kafirin microparticles encapsulating curcum was significantly improved after being exposed to UV radiation for 24 h, and no significant changes were observed in their sizes or polydispersity index (PDI) after 30-day storage under ambient conditions. However, the microparticles were easily gathered at pH 5–6. Therefore, the kafirin microparticles encapsulating curcum can improve the stability of curcum, which will provide a theoretical basis for the high-value utilization of kafirin and curcum.

Key words: curcumin, kafirin, composite microparticles, characterization