Development of protein-polysaccharide-surfactant ternary complex particles as delivery vehicles for curcumin

In this study, protein/polysaccharide/surfactant complexes were prepared by anti-solvent co-precipitation using zein, propylene glycol alginate (PGA), and either rhamnolipid or lecithin. The potential of using these ternary complexes as delivery systems for increasing the stability and bioaccessibility of curcumin (Cur) was investigated. Curcumin-loaded zein, zein-PGA, zein-PGA-rhamnolipid, and zein-PGA-lecithin complexes are abbreviated as Z-Cur, Z-P-Cur, Z-P-R-Cur and Z-P-L-Cur, respectively. The presence of polysaccharides and surfactants in the complexes increased the encapsulation efficiency of the curcumin compared to zein nanoparticles alone: Z-Cur (21%); Z-P-Cur (67%); Z-P-R-Cur (92%); and, Z-P-L-Cur (94%). X-ray diffraction indicated that curcumin was present in an amorphous state inside the complexes. Fourier transform infrared and fluorescence spectroscopy indicated that electrostatic interactions, hydrogen bonding, and hydrophobic effects were the main forces involved in complex formation. Light scattering and electrophoresis measurements showed that the particle size and charge of the complexes depended on their composition. The presence of the surfactants in the complexes significantly improved the photo-stability and bioaccessibility of curcumin. Our results suggest that the ternary complexes developed in this study might be a promising means of encapsulating, protecting, and delivering hydrophobic nutraceuticals for applications in foods, supplements, and pharmaceuticals.