Nutritional Composition and Antioxidant Capacity of Moringa Oleifera Seeds, Stem Bark and Leaves

Abstract

Moringa oleifera tree has attracted a lot of attention in the recent past with a lot of acclaimed nutritional and health benefits. This work set out to verify some of these claims and the nutritional composition and antioxidant capacity of the seeds, stem bark and leaves of the plant (Moringa oleifera) were evaluated. Results of the proximate analysis for the plant parts recorded ash content in the range 4.00 - 12.13 %, protein 7.53 - 38.23 %, moisture 29.7 - 76.48 %, crude fat 8.70 - 25.8 % and crude fibre 21.1- 27.7 %. Vitamin C content of the plant ranged from 7.85 mg/g in the stem bark to 14.42 mg/g in the seeds and 19.34 mg/g in the leaves. Mineral contents were in the range: 4.50 mg / kg - 13.7 mg/kg for copper, 19.7513.7mg/kg-73.25 mg/kg for zinc, 0.00 mg/kg- 0.25 mg/kg for cadmium and 11.75 mg/kg- 23.5 mg/kg for nickel. Lead was not detected in any of the parts. The antioxidant activities of the three parts, determined by DPPH scavenging capacity, showed that at low concentration of extract (5 μg/ml), the seeds have the highest antioxidant activity (64.53 ± 1.96 % inhibition) while the leaves have the highest activity (82.79 ± 0.79% inhibition) at a high extract concentration (125 μg/ml).
However, none of the plant parts is as active as the standard antioxidant (BHA) with antioxidant activity of 96.30 – 99.81 %.