Characterization of Edible Oils from Different Varieties of African Oil Bean Seeds

Background and Objective: Given the increasing demand for vegetable oils, investigations have been geared toward unconventional sources of vegetable oils to cushion the detrimental economic effect of the importation of these oils. This study, therefore, assessed the effects of variety on the phytochemical, physicochemical and fatty acid profile of oil extracted from three varieties of African oil bean (ugba) seeds. Materials and Methods: Edible oils were extracted from three varieties of African oil bean seeds: ugba Ghana, ugba Cameroon and ugba Nsukka. The oils were assessed for their oil yield, chemical properties, physicochemical properties and phytochemical properties while fatty acid profile was conducted for only ugba Ghana oil in consideration of its yield. Results: The oil yields were 50.23, 42.55 and 37.80% for ugba Ghana, ugba Cameroon and ugba Nsukka, respectively. Chemical properties ranged from 127.30 to 81.40 g/100 g for iodine value, 180.80-212.67 mg/KOH/g for saponification value, 3.52-6.45 meq O₂/kg fat for peroxide value, 2.14-4.53% for free fatty acid value, 0.84-3.72% for unsaponifiable matter and 0.04-1.12 mg/g for thiobarbituric acid value. Fatty acid profile of ugba Ghana oil showed that oleic acid (31.29%) was the most abundant fatty acid, followed by linoleic acid (28.69%), linolenic acid (14.1%) then tetracosapentaenoic acid (8.23%). Physicochemical properties ranged from 0.90 to 1.01 for specific gravity, 40.59 to 92.82 mPas for viscosity and 1.43-1.48 for refractive index. Phytochemical properties (mg/100 g) were alkaloid (0.00-8.42), total phenol (0.00-0.63), tannin (0.00-0.93), saponin (0.00-4.91), tocopherol (18.59-21.13) and flavonoid (0.16-0.92). Conclusion: The study has shown that variety had significant effects on the yield, physical, chemical and phytochemical compositions of the African oil bean seed oil.