Nutritional Composition and Safety Assessment of Horse Mackerel (Trachurus trachurus) and Nile Perch (Lates niloticus) Marketed in Bamako, Mali

Abstract

Aims: Fish is a primary source of animal protein in Mali, yet food safety remains a critical concern due to inadequate cold chain infrastructure and potential environmental contamination. This study aimed to determine the nutritional quality and sanitary safety of two major fish species consumed in Bamako: the imported marine Horse Mackerel (Trachurus trachurus) and the local freshwater Nile Perch (Lates niloticus). Place and Duration of Study: The study was conducted in the faculty of sciences and techniques between June 2024 and January 2026. Methodology: Samples were collected from two main markets in Bamako (Dossolo Traore and Halles of Bamako). Physicochemical parameters (pH, acidity, moisture, ash) were determined using standard AOAC methods. Nutritional composition (proteins, lipids, minerals) was analyzed via Kjeldahl, gravimetric and X-ray Fluorescence (XRF) methods. Microbiological quality was assessed by enumerating total flora, coliforms, and pathogens following ISO standards. Heavy metals were quantified using XRF spectrometry. Results: Both species exhibited high protein content (>22%), with no significant difference. Horse Mackerel was significantly richer in lipids (6.67% vs. 3.67%) and energy (152.68 kcal/100g) compared to Nile Perch. Microbiologically, Horse Mackerel was compliant with safety standards. In contrast, Nile Perch samples were heavily contaminated, showing high levels of fecal coliforms (1.07×104 CFU/g), E. coli (1.08×104 CFU/g), and the presence of Salmonella/Shigella. Heavy metal analysis revealed low concentrations of Pb, As, Cu, and Zn in both species, generally within permissible limits, although Arsenic levels (0.01%) warrant monitoring. Conclusion: While both fish species are excellent sources of nutrients, the local Nile Perch presents significant microbiological risks likely due to poor handling and environmental pollution. The imported Horse Mackerel showed better sanitary quality. Strengthening hygiene practices and cold chain management in local markets is urgently recommended.