Studies on Chemical Constituents and Nutrients Bioavailability in Moringa oleifera Leaf and Seed

Abstract

Aims: The aim of this study was to evaluate and compare the nutritional composition, antinutritional factors and antioxidant potentials of the bioactive compounds of Moringa oleifera (M. oleifera) seeds and leaves. Place and Duration: The study was carried out in the department of Food Science and Technology, Obafemi Awolowo University, Ife, Nigeria, between March-September, 2014 Methodology: M. oleifera leaf powder and seed flour were obtained by drying fresh leaves and seeds in a hot air dryer and milled. The seeds and leaves were characterized and analysed using standard methods. Results: The results showed that the crude protein, total ash, and crude fat contents of M. oleifera leaf were 20.29±0.41, 7.27±0.25 and 1.79±0.17% while those of the seed were 33.82±0.21, 5.17±0.41 and 38.69 ±0.38%, respectively. Calcium content of the seed (46.93±0.18 mg/100 g) was relatively low when compared with that of the leaf (521.96±0.32 mg/100 g). Zinc and iron concentration (14.72±0.12 and 8.12±0.11 mg/100g) in the seed were higher than in the leaf (12.28±0.02 and 7.86±0.62 mg/100g for Zn and Fe respectively). In the leaf and seed, alkaloids (0.428±0.13 and 0.597±0.04%), saponin (2.860±0.11 and 0.295±0.02%), and tanin (mg/g) were within the consumable limit. Phytate content of the leaf (0.4267±0.02 mg/g) and seed (0.4905 ±0.06 mg/g) were low enough to permit bioavailability of phosphate and not impair calcium and zinc bioavailability but may lower iron absorption in the body. Proportion of phosphate as phytate (11.95 and 13.73 mg/100g for leaf and seed respectively) was low indicating high bioavailability of phosphate. 2, 2-Diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activities of the leaf and seed were 83.61±0.31 and 69.84±1.08% respectively implying the seed and leaf possess noteworthy antioxidants activity. Conclusion: The study implies that M. oleifera leaf and seed from South Western, Nigeria are suitable for consumption with great health benefits.