Effect of different Pre-treatment Methods on the Yield and Chemical Properties of African Oil Bean Seed Oils:- Chidiebere, Gift A.

ABSTRACT

 The effect of different pre-treatment methods on the yield and chemical properties of African oil bean seed oils were evaluated. African oil bean seed were subjected to different pre-treatment methods; raw, cooking and roasting, then process into powder. Oil was extracted from each pre-treated powder via Soxhlet extraction using n-hexane as the extraction solvent. The recovered oil were analyzed for their oil yield, quality properties, chemical composition and phytochemical contents. Oil yield results include 46.88%, 42.38% and 58.19% for raw, cooked and roasted African oil bean seed oils. Quality properties ranged from 2.51 to 6.84 meq O2/kg fat, 0.25 to 7.37% and 0.03 to 1.84 mg/g for peroxide, free fatty acid and thiobarbituric acid values respectively. Iodine value, saponification value, unsaponifiable matter, smoke point and viscosity values differ significantly (p<0.05) from each other and ranged from 85.10 to 124.55 g of 1/100 g, 176.45 to 211.37 mg KOH/g, 0.84 to 2.09%, 191.86 to 233.00C and 15.55 to 35.13 Pa.s respectively. Phytochemical content showed that flavonoid content ranged from 0.01-1.40 CE mg/g, tannin content ranged from 0.00 to 1.02 mg/ 1 00 g, saponin content ranged from 0.00 to 4.49 mg/I 00 g and alkaloid content ranged from 0.00 to 8.82 mg/100 g. This study has clearly demonstrated that the type of pretreatment an oil seed is subjected to prior to oil extraction affect significantly the yield and oil properties of the extracted oil.