Modified porous starches loading curcumin and improving the free radical scavenging ability and release properties of curcumin

Maize porous starch-curcumin microspheres were prepared by encapsulating curcumin into cross-linked porous starch and oxidized porous starch to investigate the effect of modified porous starch in embedding and protecting curcumin. The morphology and physicochemical properties of microspheres were analyzed using scanning electron microscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction, Zeta/DLS, Thermal stability, and antioxidant activity; the release of curcumin was evaluated with a simulated gastric-intestine model. The FT-IR results revealed that curcumin was amorphously encapsulated in the composite and hydrogen bond formation between starch and curcumin was one of the major driving forces for encapsulation. Microspheres increased the initial decomposition temperature of curcumin, which has a protective effect on curcumin. Modification improved the encapsulation efficiency and the scavenging free radical ability of porous starch. The release mechanism of curcumin from microspheres fits first-order and Higuchi models well in gastric and intestinal models, respectively, indicating that encapsulation of curcumin within different porous starches microspheres enables controlled release of curcumin. To recapitulate, two different modified porous starch microspheres improved the drug loading, slow release and free radical scavenging effects of curcumin. Among them, the cross-linked porous starch microspheres had higher encapsulation and slow release ability for curcumin than the oxidized porous starch microspheres. It provides theoretical significance and data basis for the encapsulation of active substances by modified porous starch.