Evaluation de la valeur nutritive des poissons du lac Tanganyika (côté Burundi) : cas d’injombo (protopterius aethiopicus)

Abstract

This study aims to analyze the nutritional value of Protopterus aethiopicus, a freshwater fish from Lake Tanganyika. Samples were collected from three fishing sites: Karonda, Mvugo, and Magara. The water content, lipid content, fatty acid composition, and mineral content were determined. The analyses were conducted at the laboratory of the Faculty of Sciences at the University of Burundi and at the soil and agri-food analysis laboratory of the Institute of Agricultural Sciences of Burundi (ISABU). Additional samples were analyzed at the laboratory of the International Livestock Research Institute (ILRI) in Kenya for fatty acid profiling. The methods used were Soxhlet extraction and the official AOAC method (2019). The results show that the moisture content of Protopterus aethiopicus is 87.95 ± 5.32%, 68.32 ± 4.75%, and 81.3 ± 1.13% for the Karonda, Mvugo, and Magara sites, respectively. The lipid content is 83.24 ± 2.75%, 99.02 ± 1.11%, and 121.01 ± 1.13%, respectively, which classifies this species among lipid-rich fish. The mineral composition reveals high levels of calcium (54,717 ± 1,396.7 mg/kg), phosphorus (22,357 ± 686.44 mg/kg), and potassium (7,346 ± 151.78 mg/kg). Among trace elements, zinc (142 ± 4.45 mg/kg) and iron (72.40 ± 2.99 mg kg) also exhibit significant concentrations. However, the presence of lead (5.23 ± 0.22 mg/kg) could indicate environmental contamination. The fatty acid profile is dominated by saturated fatty acids (49.07%), followed by monounsaturated fatty acids (34.79%) and polyunsaturated fatty acids (16.12%). Palmitic acid is the most abundant, followed by oleic acid. Fatty acids of nutritional interest, such as linoleic acid, arachidonic acid, and eicosapentaenoic acid (EPA), were also identified. Consumption of Protopterus aethiopicus could thus help improve the nutritional status of local populations and combat malnutrition in Burundi and the Great Lakes region.