Abstract
The encapsulation of bioactive-rich plant extracts is an effective method of preventing their damage or loss of activity during processing and storage. Here, the techno-functional properties of microcapsules developed from Moringa oleifera leaf powder (MoLP) extract (core) with maltodextrin (MD), gum Arabic (GA), and a combination (MDGA) (coatings) were assessed. The bulk and tap density were 0.177, 0.325 and 0.297 g/mL and 0.13, 0.295 and 0.259 g/mL for GA, MD and MDGA microcapsules, respectively. Flowability properties of microcapsules indicated an intermediate flow except for GA which had a poor flow. The moisture content of the microcapsules ranged from 1.47% to 1.77% with no significant differences (p > 0.05) observed. All the microcapsules had high water solubility (86.35% for GA to 98.74% for MD and 90.51% for MDGA). Thermogravimetric analyses revealed that encapsulation enhanced the thermal stability of the core material. The X-ray diffraction analysis revealed that the microcapsules and extracts have an amorphous nature, which was validated by the surface morphology analysis that showed amorphous, irregular, and flake-like attributes except for MDGA microcapsules which had slightly spherical and agglomerated surfaces. The Fourier Transform Infra-Red spectra of the microcapsules showed the presence of C-O and O-H aromatic rings as well as amine groups. New spectra were observed at 1177, 1382 and 1411 cm−1 for MDGA, MD and GA, respectively, after encapsulation, which connotes a slight modification in the chemical structural pattern after encapsulation. Storage stability tests (28 days at 4, 25 and 40 °C) showed that the microcapsules were most stable at 4 °C and the stability differs significantly (p ≤ 0.05) with coating material type and temperature with MDGA showing better storage stability than others. Altogether, the attributes of the MDGA microcapsules were comparatively better than either MD or GA alone. The present data, therefore, demonstrate an effective encapsulation process for MoLP extract that can serve as fortificants in processed food products where MoLP may be used.
Highlights
Moringa oleifera Lam is a well-known plant that originated from the Himalayan and middle Eastern regions of the world [1,2] but has become naturalised to many countries of the world [3]
All moisture contents reported in the current study are lower than the values reported by these authors for freeze-dried microcapsules and within the ranges reported by Premi and Sharma [33] for microcapsules of M. oleifera seed oil coated with maltodextrin and gum Arabic
The values reported in the current study are within the ranges reported by Premi and Sharma, [33] It is believed that if Hausner’s ratio, Carr’s index, and the angle of repose values are greater than 1.25, 25%, and 45, respectively, the resultant product can be described as poor flowing material [37,46] the results in the present study indicate that the MD and MDGA microcapsules have medium flow properties
Summary
Moringa oleifera Lam is a well-known plant that originated from the Himalayan and middle Eastern regions of the world [1,2] but has become naturalised to many countries of the world [3]. The plant is reportedly rich in important bioactive and phytochemical compounds that have the potential for use in the development of functional foods [4,5]. The bioactive compounds in Moringa oleifera leaf powder (MoLP) were established to be potent against free-radical molecules that cause oxidative stress, resulting from an imbalance between free radicals and antioxidants in the body [3,7,8]. Examples of such major bioactive compounds in MoLP extracts are flavonoids and phenolic acids [9,10]. Some of these bioactive compounds have astringent and bitter tastes which may make foods unpalatable [13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
