Abstract

The suitability of native pear Dacryodes edulis seeds as a source of good quality vegetable oil was investigated. Oil was extracted from the dried seeds by simple solvent extraction process with hexane. Extracted oil was degummed using 0.2% H₃PO₄ or Na₂CO₃ solutions, and then bleached with activated carbon. Chemical (acid value (AV), saponification number (SN), peroxide value (PV), and iodine value (IV)) and physical (smoke point (SP), flash point (FP), melting point (MP) and freezing point) analyses were carried out on both the crude and refined oils. Results showed that the crude oil had AV of 9.6 mg KOH/g, SN of 72.8. Degumming (with 0.2%Na₂CO₃ and 0.2%H₃PO₄) and bleaching gave oils with lower AV (7.45 mgKOH/gfat) and higher acid value (9.4 mgKOH/gfat), respectively. Iodine value (48.78 ml/g) of the 0.2% Na₂CO₃ degummed oil was higher than that of the seed oil degummed with 0.2% H₃PO₄ (25.35 ml/g). Bleaching of 0.2% Na₂CO₃ degummed oil resulted in oil with peroxide value of 20 mgEq/Kg which was higher than that of 0.2% H₃PO₄ degummed and bleached (19.4 mgEq/Kg) oil.

Key words: Native pear, seeds, degumming, bleaching, deodorizing, extraction, vegetable oil.