Nutritional Composition and Antioxidant Property of Methanol Extract of Corchorus olitorius Leaf

Aims: This study investigates the phytochemicals, nutritional and antioxidant constituents of methanol extract of C. olitorius leaf using standard biochemical procedures.

Methodology: Corchorus olitorius (213.81 g) powdered leaves sample was soaked in 2.4 L of methanol respectively for 72 hr. Afterwards, the sample was filtered through a double-layered muslin cloth to obtain a filtrate which was placed in a rotary evaporator to dry off the solvent and stored. The proximate analysis, phytochemicals screening, mineral contents, antioxidant ability and phenolic compositions were determined for C. olitorius.

Results: The proximate analysis revealed that the C. olitorius extract contained 25.00% ash, 2.55% fat, 25.80% moisture, 5.50% crude fibre, 10.15% crude protein and 38.00% carbohydrate contents. Phytochemical screening indicated that flavonoids, tannins, cardiac glycosides, saponins, phenols and steroids were present in appreciable concentrations except for quinones and terpenoids. The mineral analysis of the extract showed considerable levels of potassium (1715.69 mg/100 g), calcium (33.43 mg/100 g), (sodium 49.62 mg/100 g), iron (16.78 mg/100 g) and manganese (9.44 mg/100 g) while magnesium (4.39 mg/100 g), copper (2.11 mg/100 g), zinc (2.94 mg/100 g) and lead (0.21 mg/100 g) were reduced. The extract showed high reducing power, diphenyl picrylhydrazine and H202 radicals scavenging abilities. However, the total antioxidant capacity was low compared to the standard, ascorbic acid. High performance liquid chromatography result revealed that quercitrin, quercetin, chlorogenic acid, syringic acid, epicatechin and kaempferol were present in high amounts in the extract.

Conclusion: Altogether, findings from this study indicated that C. olitorius leaf extract is a rich source of phytonutrients and mineral elements with ample antioxidative property (in vitro) that may be of relevance in the management of some degenerative conditions.