The antioxidant properties and microbial load of Moringa oleifera leaves dried using a prototype convective air-dryer
Document Type
Article
Publication Date
6-1-2022
Abstract
The recent COVID-19 pandemic resulted in major postharvest losses because most fresh produce could not be sold. Drying is an important thermal-based food preservation method which could have prolonged the shelf-life of these produce, but most drying technologies are costly, and cannot be afforded by smalltime farmers. From this context, we were interested in evaluating the drying of Moringa oleifera leaves (MOL) using a low-cost self-built prototype convective-air dryer (CAD), alongside conventional drying methods for its antioxidant properties, microbial load and phytoconstituents. Results showed total polyphenol content was the highest (p < 0.05) in our CAD samples, and it retained among the highest total flavonoid content, total antioxidant capacity, total alkaloid content and DPPH radical scavenging activity. Furthermore, methanolic CAD extract presented lower coliform and yeast and mold count than the aqueous CAD extract. We also briefly explored MOL as a sanitizer where the microbial load of the methanolic extract was comparable (p > 0.05) with several commercial non-alcoholic sanitizers, indicating its commercialization potential as a bio-friendly sanitizer. Finally, using GC-MS, we are the first to report (best of our knowledge) on the presence of caprolactam, an important bio-medical field compound, in the CAD sample's aqueous extract. (c) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license.
Keywords
Antioxidant activity, Convective air-drying, GC-MS analysis, Microbial load, Moringa oleifera leaves, Prototype dryer
Divisions
InstituteofBiologicalSciences
Funders
University of Malaya Science Faculty,GPF001B-2018
Publication Title
Saudi Journal of Biological Sciences
Volume
29
Issue
6
Publisher
Elsevier
Publisher Location
RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS