Facile microencapsulation of curcumin in acetylated starch microparticles

Highly acetylated starch was prepared by reacting corn starch with acetic anhydride. Acetylated starch (AS) is soluble in acetone and can be precipitated out from AS-acetone solution when deionised (DI) water is added as a non-solvent. The curcumin dissolved in AS-acetone solution could be effectively encapsulated in AS as spherical microparticles (1-3 μm) when mixed with the DI water. The encapsulation yield of curcumin could reach 96.3%. AS encapsulation not only resulted in five-fold lower UV degradation rate of curcumin, the free radical scavenging activity of curcumin still could be well maintained. Approximately, 40% of the 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH•) was consumed by curcumin encapsulated in AS microparticles within 2 min.