Detoxification of Jatropha curcas L. seed meal as possible alternative livestock feed in the colombian caribbean

Abstract

Jatropha curcas L. is a tropical plant presently used as a source of biodiesel; the cake, after oil extraction is rich in protein and is a potential source for livestock feed. However, this resultant cake is compound by a group of toxic substances, including phorbol esters (PMA), and some other antinutrients. In this investigation, were applied different methods of detoxification on the defatted cake of J. curcas using three chemical treatments, ethanol, methanol (both with dry thermal radiation), and sodium hydroxide / sodium hypochlorite with wet thermal radiation (water) to eliminate or reduce to a tolerable and permissible level the concentration PMA, tannins, and saponins. A physical-chemical analysis was performed to characterize the fiber content, soluble protein, lipids, nitrogen and soluble carbohydrates. The detoxification acted in a way that the activity levels of antinutrients were highly affected (p<0.05). Treatments with methanol and sodium hydroxide/sodium hypochlorite showed a low percentage on the protein content, 33.99% and 18.77% respectively, while the detoxification with ethanol reduced to 64.68%, leaving a cake in a highly acceptable level, according to the requirements for livestock feed. The reduction on the content of PMA in the samples was also successful; detoxified samples with methanol and sodium hydroxide/sodium hypochlorite, reduced the final content by a percentage of 99.80 % and 99.85% respectively, while detoxification with ethanol gave a strictest value of 99.96%, leaving this latter as the best option again.