Formulated protein-polysaccharide-surfactant ternary complexes for co-encapsulation of curcumin and resveratrol: Characterization, stability and in vitro digestibility

Abstract Pea protein isolate-high methoxyl pectin-rhamnolipid (PPI-HMP-Rha) complexes were fabricated to co-encapsulate curcumin and resveratrol, and the effect of rhamnolipid level on the physiochemical properties of PPI-HMP-Rha complexes with encapsulated curcumin and resveratrol (PPI-Cur-HMP-Res-Rha) was evaluated. The particle size and encapsulation efficiency of the complexes were assessed by dynamic light scattering and UV spectrophotometer. The PPI-Cur-HMP-Res-Rha (100:2.5:50:2.5:100) complex possessed a minimum particle size (515 nm) and a maximal encapsulation efficiency for curcumin (95.10%) and resveratrol (93.59%). The result of Fourier transforms infrared spectroscopy, revealed that hydrogen bonding, hydrophobic interaction and electrostatic attraction were main driving forces in the formation of the complexes. The X-ray Diffraction result verified that the curcumin and resveratrol in the complexes were in amorphous state. In addition, the PPI-Cur-HMP-Res-Rha (100:2.5:50:2.5:100) complex was more effective on retarding light and thermal degradation of both nutraceuticals, as well as providing a protective effect under gastric conditions, furthermore, it could control the release of both nutraceuticals in the intestine phase.