Characterisation of Crude Palm Oil Produced in Ondo State Using Physicochemical Methods

Palm oil is one of the most economically significant agricultural commodities in South West Nigeria, but quality inconsistencies arising from traditional extraction methods and poor storage practices create challenges for domestic and export markets. This study characterised crude palm oil samples obtained from small-scale processors in three palm-growing communities in Ondo State using standard physicochemical methods. A total of thirty oil samples were collected and analysed for free fatty acid content, iodine value, saponification value, peroxide value, specific gravity, refractive index, moisture and volatile matter content, and colour. Free fatty acid content, expressed as percent oleic acid, ranged from 3.2 to 7.8 percent, with values above 5 percent in 40 percent of samples indicating significant oxidative degradation. Peroxide values ranged from 8.4 to 24.6 meq O2/kg, with elevated values correlated with samples from processors using open-air drying and prolonged storage before sale. Iodine values were within the Codex Alimentarius range for palm oil at 50 to 55 g I2/100g. Saponification values ranged from 196 to 205 mg KOH/g. Colour varied from light orange to deep red, influenced by fruit ripeness and processing duration. These results indicate that a substantial proportion of crude palm oil produced in Ondo State does not meet quality standards for food-grade applications. The study recommends adoption of mechanical extraction equipment, covered drying facilities, and properly designed storage containers to reduce oxidative deterioration in small-scale palm oil processing.

Keywords: crude palm oil, physicochemical characterisation, free fatty acid, oxidation, Ondo State