Castor seeds were collected from wild castor plants growing on moist marginal land near Iluju, Ogbomosho, Oyo State, Nigeria. Harvested ripe castor fruit were cleaned by hand and sun-dried for 4-5 days, until the fruit capsules were split open to release the encased seeds. This was followed by the removal of seed pods and tray-winnowing to separate shells from beans (cotyledons). Prior to the extraction process, the beans were ground to a paste with a mortar and pestle .