[International Journal of Phytofuels and Allied Sciences] September, 2012 1 (1): 27 Consequences of Defattening and Cooking on the Proximate and Mineral Composition of Jatropha curcas Kernel Meal Ojediran, T. K and Emiola , I. A. Department of Animal Nutrition and Biotechnology Ladoke Akintola University of Technology P. M. B. 4000, Ogbomoso, Nigeria. Correspondence: walemiola@yahoo.com 07069688075, 08034104295 ABSTRACT The objective of the present study was to investigate the effect of different processing techniques on the proximate composition and mineral content of Jatropha curcas kernel meals. Three processing methods viz whole kernel meal (WKM, undefatted), defatted kernel meal (DKM) and cooked defatted kernel meal (CDKM) were used. There was no effect of processing on the dry matter (DM) content of the Jatropha curcas kernel. Compared with the WKM, the crude protein (CP) content was enhanced by processing in DKM (63.73%) and CDKM (58.0%). Crude protein content was higher in DKM (63.73%) when compared with CDKM. Ether extract was reduced by 28.50 and 16.78% in the DKM and CDKM, respectively, compared with the undefatted WKM. Extraction of oil in the DKM and CDKM resulted in an increase in the ash content by 27.92 and 20.83%, respectively. Removal of oil from the whole kernels influenced the mineral content of the meals. Nitrogen and phosphorus contents were enhanced in the DKM and CDKM compared with WKM. Compared with CDKM, defatted kernel meal was more abundant in nitrogen (6.17 vs 5.96%), phosphorus (1.24 vs 1.08%) and potassium (1.18 vs 0.86%). Processing methods reduced calcium content by 45.45% and 42.42% in DKM and CDKM, respectively. Iron content in the DKM and CDKM followed the same trend. The results of this study indicate that defatting (DKM), and cooking (CDKM) prior to defatting of Jatropha curcas kernel meal improves the crude protein and ash contents of the kernel meals. Similarly, nitrogen, phosphorus, and zinc were enhanced by the processing methods. Defatted kernel meal and cooked defatted Jatropha curcas meal could be used as components of livestock feeds for the purpose replacing for other low protein and expensive feedstuffs. However, the content of the anti-nutritional factors need further investigation in the processed kernel meal. Introduction Several plants exist with high nutritive value and yet remain underexploited for human and animal benefits. One of such plants is Jatropha curcas. Oladele and Oshodi, (2008) reported that the seed weights between 0.53 - 0.86 g and the kernel contains 22 - 27% protein and 57 - 63% oil. This indicates that Jatropha seed is of good nutritional value. The seed kernels are known to contain high levels of oil, which can be used as fuel directly or as a substitute for diesel in the transesterified form. The oil is also used for making candles, soap, lubricants and varnishes and is used for illumination. The seed cake can be a good protein source for humans as well as for livestock (Makkar et al., 2008). Although, reasons for under-utilization of Jatropha curcas seed as a feedstuffs for 27 - 34