Fabrication and characterization of curcumin-loaded composite nanoparticles based on high-hydrostatic-pressure-treated zein and pectin: Interaction mechanism, stability, and bioaccessibility

We successfully designed curcumin (Cur)-loaded composite nanoparticles consisting of high-hydrostatic-pressure-treated (HHP-treated) zein and pectin with a pressure of 150 MPa (zein-150 MPa-P-Cur), showing nano-spherical structure with high zeta-potential (-36.72 ± 1.14 mV) and encapsulation efficiency (95.64 ± 1.23 %). We investigated the interaction mechanism of the components in zein-150 MPa-P-Cur using fluorescence spectroscopy, molecular dynamics simulation, Fourier-transform infrared spectrometry and scanning electron microscopy techniques. Compared with zein-P-Cur, the binding sites and binding energy (-53.68 kcal/mol vs. - 44.22 kcal/mol) of HHP-treated zein and Cur were increased. Meanwhile, the interaction force among HHP-treated zein, pectin, and Cur was significantly enhanced, which formed a tighter and more stable particle structure to further improve package performance. Additionally, Cur showed the best chemical stability in zein-150 MPa-P-Cur. And the bioavailability of Cur was increased to 65.53 ± 1.70 %. Collectively, composite nanoparticles based on HHP-treated zein and pectin could be used as a promising Cur delivery system.