Phorbol ester degradation using chemical treatment in jatropha kernel meal

Abstract

Detoxification of jatropha (Jatropha curcas) kernel meal is of major interest for the biodiesel industry to add economic value to this residue and also to reduce the environmental damage caused by its inappropriate disposal. Anti-nutritional factors present in jatropha kernel meal are phorbol esters, lectins, trypsin inhibitor, phytate and saponins. Toxicity of meal is mainly due to the presence of phorbol esters. Several methods have been tried for detoxifying kernel meal that includes physical, chemical, biological and radiation methods. In the study, four different samples, i.e., raw, defatted, one-time mechanically oil expressed and two-times mechanically oil expressed samples were prepared from jatropha kernels. These samples were subjected to chemical treatment for phorbol ester degradation. Chemical treatment involved heating the samples with 90% methanol and 4% NaOH twice. Phorbol ester content was estimated using standard analytical procedure before and after the treatment. In chemically treated kernel meal, phorbol esters were found to be in range of 0.034-0.052 mg/g.