Chemical Composition and Fatty Acid Profile of the Lipid Fractions of Selected Nigerian Indigenous Oilseeds

Seeds of Cucumeropsis edulis, Hevea brasiliensis, Hura crepitans, Jatropha curcas, Khaya ivorensis and Citrus sinensis were evaluated for their proximate composition, chemical properties and fatty acid profiles. The moisture contents of the seeds ranged from 5.3 to 9.0% while the oil content was between 32.5% for Cucumeropsis edulis and 48.3% for Khaya ivorensis. The ash content ranged between 3.6 and 5.0%. Protein content ranged from 15.8 to 45.9% while the fibre value was in the 8.2–20.5% range. Carbohydrate content varied between 2.4 and 15.4%. The seeds were rich in potassium (349.0–468.6 μg/g of seed) and magnesium (83.7–150.19 μg/g of seed). The extracted oils had saponification value between 202.0 and 210.4; iodine value, 75.6 to 148.2; peroxide value, 4.7 to 13.3; and unsaponifiable matter content, 0.7 to 1.7%. The major fatty acids identified were oleic (14.6–72.1%) and linoleic (10.6–96.3%). Hura crepitans oil was characterized by a high content of linoleic acid (96.3%). The fuel value (Hμ) of the extracted oils ranged from 8276.6–8433.2 kJ/kg.