TITLE:
Nanoencapsulation of Antioxidant-Rich Fraction of Roasted Moringa oleifera L. Leaf Extract: Physico-Chemical Properties and in Vitro Release Mechanisms
AUTHORS:
Pierre Nobossé, Edith N. Fombang, Damanpreet Singh, Carl M. F. Mbofung
KEYWORDS:
Nanoencapsulation, Roasted Moringa Leaf Extract, Liquid-Liquid Partitioning, Antioxidant Activity, Phenolic Compounds, Physico-Chemical Properties, Release Mechanisms
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.12 No.9,
September
18,
2021
ABSTRACT: Nanocapsules (NC) of antioxidant rich fraction of roasted Moringa leaves were prepared using
emulsion coacervation technique with alginate (ALG) and/or chitosan (CTS) as
biopolymers. NC were characterized based on particle size, polydispersity index
(PDI), zeta potential, encapsulation efficiency (EE) and loading capacity (LC).
Substituting CTS with ALG in NC caused a reduction in particle size and PDI,
and enhanced EE. Mean particle size dropped from 1209 nm in 1:3 to 413 nm in
3:1 ALG/CTS-NC; PDI decreased from 0.9% to 0.2% and zeta potential from -5.4 to -28.1
mV. The highest EE (87.6%) and LC (13%) were obtained with ALG-CTS-NC (3:1).
ALG-NC were spherical while both CTS and ALG-CTS-NC were ovoid. ALG and
ALG-CTS-NC were oil/water emulsions while CTS-NC formed water/oil emulsions.
60% and 70% of bioactives in ALG-CTS-NC (3:1) were released in simulated
gastric and intestinal fluids respectively after 400 min. Release of
antioxidants from NC is concentration-dependent (First order model) and
involves simultaneously diffusion (Higuchi model), swelling (korsmeyer-Peppas
model) and erosion (Hixson-Crowell model) mechanisms.