Encapsulation of Moringa oleifera leaf extract in chitosan-coated alginate microbeads produced by ionic gelation

Encapsulation of potential bioactive natural substances is a promising preservation method for the natural additives over the synthetic antixodiants. In this study, ionic gelation has been used to encapsulate the Moringa oleifera leaf extract in biopolymers. Automatic solvent extraction was used to extract active material from the plant. Then, the active material was covered by chitosan/alginate via ionic gelation. Ionic gelation system was designed and optimized by Central Composite design of Response Surface Method (RSM). Exposure time to gelling medium (10-30 min), sodium alginate concentration (1%-2%, w/v) and chitosan concentration (0.5%1%, w/v) were process parameters to be optimized for the maximum encapsulation efficiency concerning total phenolic content (EETPC), rutin (major individual compound) concentration and inhibition effect of the capsules against DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radical. Particle shape and morphology of the dried microcapsules show that the capsules obtained are quite spherical, uniform and have a regular structure depending on stereo-microscope and scanning electron microscopy (SEM) analyzes.