Fabrication, characterization, stability and re-dispersibility of curcumin-loaded gliadin-rhamnolipid composite nanoparticles using pH-driven method

The aim of the present work was to investigate the fabrication, characterization, physical and chemical stability, and re-dispersibility of curcumin-loaded gliadin-rhamnolipid composite nanoparticles, which were prepared by pH-driven method with the novel acidifying agent (phytic acid). During the pH-driven process, the gliadin and rhamnolipid were self-assembly to form composite nanoparticles. Gliadin-rhamnolipid composite nanoparticles showed a higher encapsulation efficiency (98.70%) of curcumin than that (64.70%) of gliadin nanoparticles. Fourier transform infrared spectroscopy and potentiometric analysis revealed that hydrogen bonding, hydrophobic and electrostatic interactions were mainly involved in the formation of curcumin-loaded gliadin-rhamnolipid composite nanoparticles. Compared to the impact of the novel acidifying agent (phytic acid) and the conventional acidifying agent (hydrochloric acid) on the attribute of curcumin-loaded gliadin-rhamnolipid nanoparticles, the nanoparticles prepared with phytic acid had better thermal stability, photostability, physical stability and re-dispersibility than those prepared with hydrochloric acid. The physicochemical properties of the composite nanoparticles also depended on the mass ratio of gliadin to rhamnolipid. Furthermore, rhamnolipid exhibited an obviously positive effect on enhancing the stability of curcumin and the re-dispersibility of gliadin-based nanoparticles. Consequently, by using the pH-driven method with phytic acid, the fabricated gliadin-rhamnolipid composite nanoparticles have potential as a better nano-delivery system for curcumin in functional foods.