The Proximate Analysis, Phytochemical Screening, Antioxidant Activity and Mineral Composition of Momordica charantia and Ocimum gratissimum Leaf Powder

Abstract
Aim: This study aims to evaluate and characterise the Momordica charantia and Ocimum gratissimum leaf powder. Methodology: The quantitative analyses for proximate, phytochemicals, minerals, and antioxidant activities of Momordica charantia and Ocimum gratissimum leaf powder were carried out using standard procedures. Results: The result of the proximate analysis showed that both plants contain an appreciable amount of moisture, ash, crude fibre, crude fat, crude protein and nitrogen-free extract content, with M. charantia leaf powder having higher moisture (5.49 ± 0.03%) content than O. gratissimum leaf powder (5.02 ± 0.01%) (P < 0.05). Ocimum gratissimum had higher crude fibre content (25.03 ± 0.25%) than M. charantia leaf powder (20.86 ± 0.12%) (P < 0.05). The protein, ash, crude fat and nitrogen-free extract contents were not significantly different (p> 0.05) between the two leaf powders. The phytochemical screening revealed the presence of tannin, flavonoid, phenol, alkaloids, saponin and phytate. Except for alkaloid content, M. charantia leaf powder had higher tannins (1.20±0.02 mg/g), flavonoids (225.64±14.61 mg/g), phenol (21.04±0.57 mg/g), saponins (57.36±0.08 mg/g) and phytate (7.79±0.25 mg/g) content compared to O. gratissimum leaf powder. The antioxidant activity of the plants showed that M. charantia leaf powder possessed higher DPPH scavenging free radical activity than that of O. gratissimum leaf powder. The mineral constituents revealed that both plants contain a significant amount of zinc, calcium, iron and phosphorus, with M. charantia leaf powder having higher zinc and calcium concentration than O. gratissimum leaf powder (p < 0.05). In conclusion, this study shows that the leaf of M. charantia and O. gratissimum plants are rich sources of nutrients and phytochemicals and can be used as natural feed additives in animal nutrition.