Pectin-sodium caseinat hydrogel containing olive leaf extract-nano lipid carrier: Preparation, characterization and rheological properties

Abstract Olive leaf extract (OLE), as a natural antioxidant, was encapsulated within nanostructured lipid carrier (OLE-NLC) and the physico-chemical, microstructure, physical stability, antioxidant activity, and encapsulation efficiency (EE%) were evaluated. Then, it was loaded into the pectin-sodium caseinate hydrogel network and its antioxidant and physicochemical properties were examined during storage. The particle size, polydispersity index (PDI), and zeta-potential (ζ) of the OLE-NLC nanoparticles and OLE-NLC containing hydrogel were 112.9 and 303 nm, ~0.34 and 0.58, respectively. Spherical particles with flat surface were observed by scanning electron microscopy (SEM) for both systems. During 40 days of storage at 4 °C, the NLC particle size was stable and remained