Changes in Biochemical Composition in Indian Major Carps in Relation to size

Abstract

Total biochemical composition of freshwater major carps, Labeo rohita -(rohu); Catla catla (catla); Cirrhinus mrigala (mrigal), in relation to size was evaluated. The water soluble nitrogen iraction constituted about 21% of the total nitrogen. Salt soluble fraction constituted 55 - 60% of the total nitrogen. Non-protein nitrogen represented 12% of the total nitrogen in all the cases except mrigal of small size (9.36%). The insoluble connective tissue contributed to 2-3 per cent of total nitrogen. The monounsaturated fatty acids (MUFA) formed 31-39% of the total fatty acids and 60-68% of the MUFA in freshwater carps was C18:l. The essential amino acids contributed to 41 to 51% of the total amino acids in freshwater major carps. Aromatic amino acid content was slightly higher compared to marine fishes while the proportion of proline was less. Variations in composition in relation to size are discussed. The autolytic activity was significantly higher in small fish in all the three species