Avaliação do valor energético do peixe bagre de água doce (Clarias gariepinus) e de água salgada (Arius dussumieri)

Abstract

This monograph entitled: “Evaluation of the energy value of freshwater (Clarias gariepinus) and saltwater (Arius dussumieri) catfish”, deals with the energetic aspects of fish, as they are particularly nutritious and used in prevention of some diseases. Particularly, catfish have high nutritional properties similar to some species of economic importance, but unfortunately, are poorly appreciated for consumption by inhabitants of Quelimane due to some characteristics (strong odor, physical appearance) of freshwater (Clarias gariepinus) and Saltwater (Arius dussumieri) catfish. A total of 20 fish samples were taken from Zalala beach and the Licuar River located in Quelimane City and analyzed in the chemistry laboratory of High School of Marine and Coastal Sciences (ESCMC) and subjected to cleaning (evisceration and washing), homogenization, drying (at 1000C for 14 hours). The sample was then divided into 2 parts, the first being used for the determination of calories by direct combustion of 0.08g weighed for each 8 samples of freshwater and saltwater catfish, in a home calorimeter constructed from low cost material, in the temperature variation of a 20 ml sample of distilled water shall be measured. The energy value was calculated from the formula Q= m.c.ΔT. The second part was used for cold lipid extraction by methanol, chloroform and potassium chloride solvents according to the methodology described by Bligh and Dyer (1959). The energy values in fish as measured by the calorimeter were 146.6 and 226.1 Kcal*100g-1 for the saltwater catfish (Arius dussumieri) and freshwater catfish (Clarias gariepinus) respectively. In the extraction of lipids, 39.21g corresponded to 78.42% for freshwater catfish and 16.96g, corresponding 33.92% for saltwater catfish. It follows that freshwater catfish have more calories and lipids than saltwater catfish, which is in accordance with the literature.