Comparative evaluation of Jatropha curcas L. seed meals obtained by different methods of defatting on toxic, antinutritional and nutritive factors.

Different methods of defatting have a great impact on toxic, antinutritional and nutritive factors in the oilseed meals. In order to find the most suitable methods of defatting for Jatropha curcas seed meals, the Jatropha curcas L. seed meals, defatted by Soxhlet extraction and screw-press were characterized for their toxic, anti-nutritional and nutrient factors in this study. The toxins (phorbolesters, 3.1 and 2.9 mg/g) and some anti-nutritional factors (saponins, 2.9 and 2.6%; phytates, 11.1 and 11.6%) in meals obtained by the two defatting methods were present at high concentrations. However, the trypsin inhibitors activity (TIA) and lectin (2.7 mg/g and 1.5 mg/ml) in the screw-pressed meal were significantly lower, due to the high temperature (120 °C) used in this defatting process. From nutritional side, the values of crude protein (CP), buffer-soluble nitrogen, non-protein nitrogen, pepsin insoluble nitrogen, in vitro protein digestibility (IVPD), as well as essential amino acid index (EAAI), biological value (BV), nutritional index (NI) and protein-digestibility-corrected amino acid score (PDCAAS) of the meal obtained by Soxhlet extraction were better than the screw-pressed meal. However, taking practical application into account, from detoxification side, screw-pressed meal is better for detoxification.