40 June 2012 toxic components, such as PEs, phytates, saponins and lectins (Siddhuraju et al. 2002). Heat labile antinutrients, protease inhibitors and lectins are easy to inactivate by moist heating (Aderibigbe et al. 1997, Aregheore et al. 2003). But, it is not possible to destroy PEs by heat treatment because they are heat stable and can withstand roasting a temperature as high as 160 o C for 30 min. However, it is possible to reduce their concentration in the meal by chemical treatments, which are not feasible economically (Aregheore et al. 2003). Furthermore, Martınez-Herrera et al. (2006) studied the effect of various treatments, such as hydrothermal processing techniques, solvent extraction, solvent extraction plus treatment with NaHCO3 and ionizing radiation to inactivate the antinutritional factors in Jatropha kernel meal of both toxic and nontoxic varieties from different regions of Mexico; but, unfortunately, were unable to remove PEs from Jatropha kernel meal. Recently, a method for detoxification of Jatropha kernel meal has been developed (Makkar et al. 2008). This detoxification method is based on extraction of PEs using organic solvents and inactivation of trypsin inhibitors and lectin by heat treatment. Role of Detoxified Jatropha Kernel Meal (DJKM) in Aquafeed Aquaculture is growing rapidly at an average rate of 8.9 Table 3. Amino acid composition (g kg-1) of Jatropha kernel meal (J-Toxic and J-nontoxic), detoxified Jatropha kernel meal (DJKM) soybean meal and fish meal Amino acids J-Toxic J-Non-toxic DJKM Soybean meal Fish meal Essential (g kg-1) Arginine 73.7 80.6 69.7 44.5 35.3 Histidine 20.6 19.2 21.7 15.6 17.7 Isoleucine 28.1 30.0 26.7 28.8 22.8 Leucine 43.2 46.2 46.7 48.2 41.6 Lysine 26.1 21.1 23.3 38.0 40.9 Phenylalanine 27.2 30.2 30.4 30.2 21.8 Methionine 11.9 11.0 10.6 7.6 16.0 Threonine 24.4 22.3 22.0 23.5 23.0 Tryptophan 8.2 ND 7.1 7.8 4.9 Valine 32.3 33.5 31.6 28.6 29.3 Cystine 14.0 9.8 2.3 10.6 4.3 Non-essential (g kg-1) Alanine 32.5 30.8 29.4 26.4 43.3 Asparginine 59.3 62.0 68.7 70.6 60.5 Glycine 30.7 28.8 31.5 25.0 59.8 Glutamine 91.7 99.4 112.1 105.6 79.4 Proline 31.0 23.7 32.2 30.3 36.9 Serine 30.0 30.1 30.6 35.4 25.5 Tyrosine 18.6 23.6 18.8 21.1 14.8 Makkar and Becker 2009 and Kumar et al. 2010a *ND: Not detected percent per year, compared with only 1.2 percent for capture fisheries and 2.8 percent for terrestrial farmed meat production systems (FAO 2007). Fishmeal is still a preferred protein source for fish diets corresponding to its high protein quality to meet the intensification of aquaculture systems (NRC 1993). However, because of the high cost and limited availability in many countries (Naylor et al. 2000), the replacement of fishmeal by plant protein sources is of great interest. Detoxified Jatropha kernel meal (DJKM) is a novel and highly nutritious plant protein source. Except for lysine, the level of EAA contents in DJKM was either greaterer or comparable to fishmeal and soybean meal (Kumar et al. 2010a; Table 3), indicating that the material can be used as excellent fishmeal and soybean replacer in fish and shrimp diets. Up to 50 percent of fish meal could be replaced by DJKM in common carp (Cyprinus carpio L.), rainbow trout (Oncorhynchus mykiss) and whiteleg shrimp (Litopenaeus vannamei) without influencing the growth rate and nutrient utilization (feed conversion ratio and protein efficiency ratio) (Kumar et al. 2010a,b); Harter et al. 2010, Harter et al. 2010). Growth performance and nutrient utilization of shrimp groups fed DJKM at 50 percent replacement of fishmeal protein were better than that of the fishmeal fed group (Table 4). The higher growth response of the DJKM fed (Continued on page 42)
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