Proximate composition, amino acid and mineral contents of five commercial Nile fishes in Sudan

Abstract

The objective of this study was to determine the meat quality of the Nile fishes:Lates niloticus, Bagrus bayad, Oreochromis niloticus, Synodontis schall andTetraodon lineatus, which represent different grades of preference to the Sudanese consumers. Lipid content was 1.8 to 17.3% and moisture was 73 to 80%. Protein content was 59.8% in S. schall and 77 to 79.1% in the remaining species. The caloric value was 357 to 425 Kj/100 g, which is high in B. bayad and least in T. lineatus. Minerals included potassium (33 to 41%), phosphorous (25 to 36%), selenium (12 to 16%), calcium (4 to 19%), sodium (2 to 10%), and magnesium (2 to 3%); while zinc, iron, aluminum and copper were present in trace amounts. Eight essential amino acids with total amount of 961 to 2279 µg/g were identified, and lysine formed the highest value in all the species, followed by leucine. Essential amino acids (EAA) formed 38 to 46% of the total amino acids, high in L. niloticus and low in S. schall. The data showed that the Nile fishes are of high nutritional value and good source of proteins, minerals as well as essential amino acids. It is recommended to assess the meat quality of other species, especially presently unused ones prior to processing and storage, because the contents of moisture, fats and other components in the tissues could affect the post-harvest processing and storage of the fish. Key words: Essential amino acids, lipids, minerals, moisture, Nile fishes, proteins, proximate composition, Sudan.