Abstract: Folic acid conjugated with amphiphilic polysaccharide has been regarded as an effective carrier to delivery hydrophobic pheytochemicals to the colon. In our present study, the stability of self-assembled micelles of folic acid octenylsuccinate inulin (FA-OS-inulin) loaded with curcumin to thermal treatment, freeze-thaw treatment and simulated gastrointestinal digestion was investigated by the particle size and polydispersity index (PDI) of micelles as well as the retention of curcumin. Results showed that the micelles exhibited good thermal and storage stability with enhanced retention of curcumin. However, the particle size and PDI changed significantly during thermal processing and storage (P < 0.05). In the end of the gastrointestinal digestion, the percentage release of curcumin from the micelles was lower than 2% and 10% in simulated gastric and intestinal fluids respectively, indicating good controlled release properties. Therefore, FA-OS-inulin may be used as a potential vehicle for colon-targeted delivery of bioactive compounds like curcumin.

Key words: folic acid octenylsuccinate inulin; micelles; curcumin; stability; colon-targeted delivery