ABSTRACT

This research work was undertaken to asses the impact of methods of processing on the quality of oil from Pentaclethra macrophylla seeds. Pentaclethra macrophylla seeds were boiled for different time intervals (1 - 5 hours) and fermented for different periods (0-4) days. Oil was extracted after each processing treatment and evaluated for free fatty acid content, iodine value, emulsion capacity, peroxide value and alkaloid content. Sensory evaluation was performed on sauces prepared from the oil bean seed product fermented for different periods (3,5 and 7 days respectively). Oil yield tab 4.1 increased from 40% in the unfermented seeds to 60% in the fermented seeds for 2 days. The FFA of most of the oil samples were not significantly (P>0.05) affected by the processing operations. The Iodine values ranged from 40.59 ± 0.01 - 96.05 ± 0.16 showing that the oil contained mainly monounsaturated fatty acids. The Emulsion capacity of the seeds increased significantly (P<0.05) with successive processing steps. Peroxide values obtained after two months of storage of Pentaclethra macrophyila oil, at room temperature (28±2°C) indicated rancidity (>20 meq/kg); which reduced with subsequent treatments. There were significant difference (P<0.05) in the alkaloid content of Pentaclethra macrophylla seeds which decreased from 59.50± 2.12- 0.90±0.14, given different processing treatment.Overall, seeds boiled for 5 hours and fermented for 2 days gave an optimum oil yield (18.74±0. 13) and quality, (FFA- 0.28±0.09, PV-4.76±0.05, AC-4.00± 1.41) while, seeds boiled for 5 hours and fermented for 3 days produced Ugba sauce with optimum organoleptic quality (Colour -8.10±0.64, Taste7.80±0.89, flavour-7 .60±0.88, Texture- 7.70±1.03). ><0.05) in the alkaloid content of Pentaclethra macrophylla seeds which decreased from 59.50± 2.12- 0.90±0.14, given different processing treatment. Overall, seeds boiled for 5 hours and fermented for 2 days gave an optimum oil yield (18.74±0. 13) and quality, (FFA- 0.28±0.09, PV-4.76±0.05, AC-4.00± 1.41) while, seeds boiled for 5 hours and fermented for 3 days produced Ugba sauce with optimum organoleptic quality (Colour -8.10±0.64, Taste7.80±0.89, flavour-7 .60±0.88, Texture- 7.70±1.03).