ANTINUTRITIONAL FACTORS, TOXIC ELEMENTS AND PHYTOCHEMICALS PRESENT IN JATROPHA CURCAS FRUITS, KERNELS, SEEDS AND ETHANOL SEED EXTRACT

Abstract

ABSTRACT Jatropha curcas (J. curcas) seeds have been exploited as a source of biodiesel and for its ethnomedicinal uses and agro feed potential, however, toxic properties have been associated with the seeds. The study was aimed at determining the toxic constituents present in J. curcas fruits, seeds and kernels and ethanol seed extract. Standard methods were employed in the investigations, including those of the Association of Analytical Chemists and Trease and Evans. J. curcas fruits, seeds and kernels from Sierra Leone contained cyanogenic glycosides (in mg/100g) of 7.10, 5.10 and 16.96 while the corresponding values for the Nigeria samples were 11.60, 10.15 and 15.92; all greatly above the maximum permissible limits of 0.05-0.35. Similarly, the tannin contents of the fruits, seeds and kernels from Sierra Leone (1.66, 1.46, and 1.80) and of the seeds and kernels from Nigeria (1.40, 1.48) approximated the maximum permissible limits of 1.5 mg/100g or were higher. In contrast, the phytates and saponins which ranged from 1.78-2.14 and 1.64-2.42 for both sources of J. curcas were significantly below the maximum permissible levels of 500 mg/100g (for phytates) and 100 mg/100g (for saponins). Heavy metals like cadmium, copper, chromium and lead were also detected, but their concentrations were below the maximum permissible limits. These constituents were mostly similar regardless of the country source of Jatropha. Ethanol extract of J. curcas seeds was found to contain toxic phytochemicals and heavy metals. J. curcas as food cannot be ruled out especially for animals since cooking, fermentation and heat treatment can significantly reduce some of these antinutritional factors.