Described are methods for extracting oil and phorbol esters from oil seed kernel, for example from Jatropha curcas oil seed kernel. The methods comprise treating the oil seed kernel with at least one solvent and separating the resultant solvent/oil mix from the treated kernel to leave a seedcake substantially free of phorbol esters. Also described are seedcakes produced by the methods which can be used as nutritional compositions, for example as animal feeds.