Assessment of the Proximate, Some Essential and Heavy Metals Composition of Some Fresh Local Varieties of Fish Sold in Sabon Gari Market Kano, Nigeria

摘要

Aims: Comparisons of the proximate and heavy metal composition were made among some five local varieties of fresh fish sold in Sabon Gari market Kano, Nigeria. This is to ascertain whether such fishes contribute to the nutritional value or heavy metal toxicity of the local populace. Study Design: Samples were obtained from the market, taken to the laboratory and processed for both proximate and elemental analysis. Place and Duration of Study: The fishes were obtained from Sabon Gari market, located in Kano State, Northwestern Nigeria. Methodology: The proximate composition of the fishes used as samples were determined in triplicate using Association of Analytical Chemists methods while elemental analysis was conducted using Atomic Absorption Spectroscopy (Jenway 6405). Results: The proximate composition analysis revealed that, moisture content range from 57.36% for the flesh of Oreochromis niloticus to 71.53% for that from Alestes baremose ; proteins range from 16.72% to 20.80% for flesh from Oreochromis niloticus and Clarias gariepinus ; fat content of range from 3.09% to 20.94% for flesh from Alestes baremose and Oreochromis niloticus . The carbohydrate content were found to range from 1.48% for the flesh from Alestes brevis to 4.54% for that from Clarias gariepinus and ash range from 0.46% to 5.46% for the flesh from Clarias gariepinus and Shilbe isideri respectively. The elemental analysis revealed a variation in elemental concentration among the fish samples used. All data obtained for heavy metals were significantly lower (p<0.05%) than the corresponding internationally agreed limit. High concentration of zinc (Zn), iron (Fe), manganese (Mn), calcium (Ca) and cobalt (Co) was detected from Oreochromis niloticus. The sample from Clarias gariepinus was found to contain high amount of both lead and nickel as compared to others. The level of copper and cadmium were detected to be high in sample from Alestes brevis while high level of magnesium was detected from Shilbe isideri sample as compared to other sources. Conclusion: The fishes sold in Sabon Gari market are nutritious with low level of heavy metals and thus, may serve as a good source of essential nutrients.