To improve starch functionalities such as digestibility and antioxidant activity, rice starch was complexed with antioxidant dodecyl gallate (DG). Molecular dynamics simulation showed that the starch-DG inclusion complex was favorable, and in 50 ns, the dodecyl segment resided in the helix of the amylose cavities but the gallate tail left outside. This theoretical finding was validated by UV-vis spectroscopy, calorimetric, and crystalline measurements, indicating V-type crystalline structures containing type I and type II inclusion complexes can be formed after DG complexation. Meritedly, starch digestibility was mitigated by synchronously increasing slowly digestible starch (5.12-22.83%) and resistant starch content (8.69-14.17%), and the antioxidant activity was also significantly increased. Such inclusion complexes thereby acted as a carrier for targeting delivery of DG to the human lower gastrointestinal tract with potent antioxidant activity. Complexation with DG synergistically improved starch digestibility and antioxidant activity, favoring the intervention against chronic diseases, by ameliorating the postprandial glycemic response and oxidative stress.

Curcumin displays anti-cancer, anti-inflammatory and anti-obesity properties but its water insolubility limits the wholesome utility. In this study, curcumin has been encapsulated in an amphiphilic biopolymer to enhance its water solubility. This was accomplished through self-assembly of octenyl succinic anhydride–short glucan chains (OSA–SGC) and curcumin. The nanoparticles were prepared with the degree of substitution (DS) of 0.112, 0.286 and 0.342 of OSA. Thus prepared nanoparticles were in the range of 150–200 nm and display high encapsulation efficiency and high loading capacity of curcumin. The Fourier-transform infrared (FTIR) and X-ray diffraction analyses confirmed the curcumin loading in the OSA–SGC nanoparticles. The complexes possessed a V-type starch structure. The thermo gravimetric analysis (TGA) revealed the thermal stability of encapsulated curcumin. The OSA–SGC nanoparticles greatly improved the curcumin release and dissolution, and in-turn promoted the sustained release.