Effect of roasting temperature on the physicochemical properties of Jatropha curcas Kernel oil extracted with cold hexane and hot water

Abstract

The industrial application of a vegetable oil is determined by the oil properties. This work was undertaken to alter the properties of Jatropha curcas Kernel oil and possibly find new applications for it. The seed kernels were roasted to different temperatures (140 to 230°C) and the physicochemical properties of the cold hexane and hot water extracted oils were studied. The oil yield, saponification, iodine, acid and peroxide values were affected by roasting temperature and method of extraction and these showed significant difference (p < 0.05). The calculated fuel properties: cetane number and calorific value were improved upon roasting, with cold hexane extracted oils yielding better results. Roasting improved the properties of the oil as diesel substitute but its suitability for use in paints and surface coatings formulation was reduced. The hot water extracted oil showed improved properties for soap production. Key words: Jatropha curcas, roasting temperature, oil extraction, physicochemical properties.