Chemical Composition and in vitro Antioxidant Properties of Hexane and Methanol Extract of Sesamum indicum Seeds Obtained from Kogi State, Nigeria

The chemical composition and in vitro properties of hexane and methanol extract of Sesamum indicum seeds (SIS) obtained from Kogi State, Nigeria were evaluated. The proximate analysis of the ground seed showed the presence of moisture content (8.56 ± 0.02%), dry matter (91.44 ± 0.02%), ash content (5.70 ± 0.01%), crude protein (19.37 ± 0.08%), crude fiber (6.34 ± 0.03%), fat (52.77 ± 0.02%) and carbohydrates (7.26 ± 0.14%). Phytochemical analysis of both extracts showed the presence of oxalate, hydro cyanide, alkaloids, tannins, total flavonoids, phenol, steroids and terpenes. Flavonoids and phenol contents were higher in both extracts. The flavonoid and phenol concentrations of hexane and methanol extracts were 24.79 ± 0.01 and 25.27 ± 0.02 mg/100 g, 24.32 ± 0.02 mg/100 g and 18.66 ± 0.04 mg/100g, respectively. Hydrogen cyanide was found in lowest concentration in both extracts. Vitamins analysis showed that vitamin E had the highest composite for hexane and methanol extract. Vitamin E concentration was 3.44 ± 0.01 mg/100g and 2.95± 0.02mg/100g respectively while vitamin B6 (0.01 ± 0.00 mg/100g) and vitamin B1 (0.03 ± 0.00 mg/100g) were found in lowest concentration respectively. The mineral analysis showed that potassium (43.33 ± 0.04 and 27.46 ± 0.02 mg/100g) had the highest concentration for methanol and hexane extract, respectively. The results of the DPPH activity of methanol and hexane extract of S. indicum seeds indicated that the activity of the extract were all significantly (p<0.05) lower than the values for ascorbic acid (standard) across all concentrations. However, the DPPH activity of hexane extract indicated that there was no activity in the tested concentrations below100 µg/mL. The result of the FRAP of methanol and hexane extract of SIS showed that there was no activity at the concentrations of 100 µg/ml and 400 µg/ml respectively. However, the activity observed at concentrations above 100 µg/ml and 400 µg/ml were all significantly (p<0.05) lower than the same concentration in ascorbic acid. This result implies that hexane and methanol extract of S. indicum seeds possess nutritional and pharmacological value and can be a rich source of minerals, vitamins and antioxidative supplement.