Production and refining of Dacryodes edulis “native pear” seeds oil

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 (25.35ml/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.