Effect of Cooking Method on the Proximate, Amino Acid and Fatty Acid Compositions of Clarias gariepinus and Oreochromis niloticus

The proximate, amino acid and fatty acid compositions of the fillet and oil from Clarias gariepinus (Catfish) and Oreochromis niloticus (Tilapia) were determined. The moisture content ranged from 76.27 % for catfish to 79.97 % for tilapia while the oil content ranged from 7.80 % for tilapia and 11.00 % for catfish. Ash content was in the range 8.03 – 9.16 % and the protein content was 15.83 - 18.48 %. Cooking – boiling, roasting or frying – resulted in a variation in the nutrient composition but with no significant effect on the amino acid composition except for the samples fried with palm oil which resulted in significantly reduced essential amino acids contents. All the fish samples – both fresh and processed – have amino acid scores less than 100, with lysine, threonine and the sulphur-containing amino acids being among the limiting amino acids. Both fish samples contain more unsaturated than saturated fatty acids.