Comparative assessment regarding antioxidative and nutrition potential of Moringa oleifera leaves by bacterial fermentation

J Food Sci Technol. 2020 Mar;57(3):1110-1118. doi: 10.1007/s13197-019-04146-1. Epub 2019 Nov 27.

Abstract

Moringa is considered as a miraculous plant because of its outstanding health-promoting properties. Moringa leaves are used in various forms for various purposes owing to its potential against that purpose. This experiment was performed to utilize the hidden potential of Moringa leaves. The Moringa leaves were fermented by Bacillus subtilis KCTC 13,241 for 24, 48, 72 and 96 h to identify the best time duration of fermentation. The antioxidant potential of fermented Moringa leaves was estimated by measuring the total phenolic content (TPC), total isoflavones content (TIFC), DPPH and ABTS free radical scavenging activity and SOD-like activity. In addition to these parameters, the concentration of various total amino acids (TAA) and fatty acids were also determined. The best treatment was 48 h fermented Moringa leaves because of the best results in all measured parameters except in fatty acids concentration. The highest fatty acids concentration was recorded in 24 h fermented leaves. The results of 48 h fermented Moringa leaves regarding TAA, TPC, TIFC, DPPH and ABTS radical scavenging potential and SOD-like activity were 121.95 ± 3.74 mg/g, 310.25 ± 3.77 μg GAE/g, 1083.38 ± 5.92 µg/g, 63.12 ± 2.38%, 78.45 ± 3.32%, and 34.55 ± 1.05% respectively. The palmitic, stearic, oleic, linoleic and linolenic acid concentration in 24 h fermented Moringa leaves was 55.32 ± 1.93, 56.02 ± 2.12, 53.82 ± 2.54, 55.95 ± 1.62 and 56.41 ± 1.43% respectively. In conclusion, the present results disclose that fermented Moringa leaves are the source of natural antioxidants and nutrients.

Keywords: Antioxidants; Fermentation; Isoflavones; Medicinal plant; Moringa oleifera.