COMPARATIVE STUDIES ON THE NUTRITIONAL AND PHYTOCHEMICAL COMPOSITIONS AND THE ANTIOXIDANT POTENTIALS OF FERMENTED CASTOR OIL AND SOURSOP SEEDS

This work compared the nutritional and phytochemical compositions, antioxidant capacities of fermented castor oil and soursop seeds. The seeds of castor oil and soursop were fermented traditionally and standard methods were applied for the determination of the phytochemical, proximate, vitamins, minerals and in vitro antioxidant activity. The phytochemical compositions showed total phenols (11.60±1.52 and 22.17±0.64 mgGAE/100g), flavonoids (3.60±0.11 and 3.37±0.07 mgCE/100g), tannins (4.77±0.13 and 1.33±0.40 mg/100g), alkaloids (0.30±0.03% and not detected), oxalate (0.54±0.00 and 0.68±0.20 mg/g), phytate (0.33±0.02 and 0.09±0.01%) and saponin (0.54±0.62% and not detected) for fermented castor oil andsoursop seeds respectively. Proximate compositions showed crude fibre (0.73±0.11 and 7.25±0.35%), ash (2.29±0.22 and 1.64±0.12%), lipid (17.80±1.13 and 11.55±0.77%), moisture (43.29±0.72 and 38.60±1.81%), carbohydrate (31.25±2.28, 23.84±1.12%) and crude protein (16.75±1.41 and 5.03±0.31%) for fermented castor oil and soursop seeds respectively. The vitamin analysis revealed vitamins A (6.37±0.00 and 16.56±0.00 mg/g), B1 (3.89±0.00 and 9.44±0.43µg/g), C (5.43±0.31 and 2.39±0.31mg/g), E (5.39±0.04 and 0.52±0.04 mg/g) and folic acid (31.22±1.60 and 42.33±1.60µg/g). The mineral composition showed Ca (180.00±2.52 and 2.72±0.36mg/kg), K (281.63±0.40 and 2.95±0.09mg/kg), P (214.80±6.15 and 214.39±3.80mg/kg) and Zn (0.87±0.06 and 214.39±3.80mg/kg) respectively. The fermented castor oil and soursop seeds significantly (p<0.05) increase inhibition of lipid peroxidation and also had a high reducing power capacity. The result indicated that fermented soursop seeds can serve as a substitute for fermented castor oil seeds especially for individuals with vitamins deficiency.