Nutritional composition of different size groups of catfish Rita rita (Hamilton, 1822) from river Ganga

The freshwater catfish Rita rita (Hamilton, 1822) (Family: Bagridae) inhabits the tropical rivers and estuaries and contributes to the capture fisheries production in the Indian subcontinent. It enjoys high consumer preference as a valuable food fish due to its muscle texture, good taste and lesser intramuscular spines; however, basic nutritional information on the species is not available. In the present study we report the proximate composition, amino acid, fatty acid and mineral composition of different size groups of R. rita. Proximate analysis showed that the fish is rich in protein and low in fat. The protein content (19.55%) was found to be the highest in medium size fishes. Leucine, phenylalanine and glutamic acid are the predominant amino acids in all size groups and leucine (18.67 g 100 g-1 protein) and glutamic acid (10.55 g 100 g-1 protein) contents were significantly high in medium size fishes. The macro-minerals potassium (13800 ppm) and phosphorous (14100 ppm) were significantly high in the medium size group, whereas calcium (1900 ppm) was highest in large size group. The micro-minerals iron and zinc were present in significantly higher amount in the medium size fishes. R. rita is important as a rich source of protein, essential amino acids (leucine, phenylalanine, glutamic acid) and micro elements (Zn, Fe). Comparative nutritional evaluation of different size groups showed that the medium size fish (weighing 500-800 g) were nutritionally superior to the other groups.