Nutritional and biochemical studies on feeding of hydrolysed and unhydrolysed detoxified Jatropha curcas protein isolate in common carp fingerlings

摘要

Detoxified Jatropha protein isolate (DJPI), prepared from Jatropha seed cake was hydrolysed using Alcalase 2.4L FG. Both DJPI and hydrolysed DJPI (HDJPI) were evaluated as a fish meal (FM) replacement in common carp (Cyprinus carpio L.) diets. The peptide concentration in HDJPI was determined using matrix-assisted laser desorption ionization-time of flight mass spectrometer (MALDI-TOF). Twenty-two peptides with molecular mass ranging from m/z 906.455 to 1774.943 Da were identified. Fingerlings (45; av. wt. 10.1 +/- 0.4 g) were randomly distributed in five groups with three replicates. An 8-week feeding experiment was conducted to compare the nutritional quality of the HDJPI, DJPI and FM. Fish were fed on iso-nitrogenous diets: control (FM based protein), J(50) (50% of FM protein replaced by DJPI), J(75) (75% of FM protein replaced by DJPI), JH(50) (50% of FM protein replaced by HDJPI) and JH(75) (75% of FM protein replaced by HDJPI). Growth performance was higher for FM fed group compared with the other groups, while nutrient utilization parameters were similar for control and J(50) groups and superior (P < 0.05) to J(75) and both the HDJPI fed groups. No variation (P > 0.05) was observed in blood albumin and hepatosomatic index among all different groups. Blood urea nitrogen, calcium, sodium and potassium ions in the blood were similar among all five groups.