Microbial Flora and Nutrient Content of Market Bought Smoked African Cat Fish Clarias gariepinus from Jos, Nigeria

Abstract

Clarias gariepinus, one of the many fishes sold in Nigerian market, is the most preferred smoked fish in Jos where large quantities are smoked and stored for sale. This study assessed the nutritional value and health of smoked C. gariepinus sold in Jos markets.Live and smoked C. gariepinus were purchased from the four major markets in Jos metropolis. Microorganisms isolated from the smoked fish were identified. The live fish were smoked in the laboratory and inoculated with the isolated microorganisms. Nutrient content of the fishes were monitored weekly for four weeks, un-inoculated laboratory smoked fish served as controls.Bacillus brevis, Aspergillus fumigates and Mucor species were isolated from purchased smoked fish. The nutrient value of these fish were significantly lower (p<0.05) than the laboratory smoked fish. There was however a gradual decline in the nutrient content of the infected laboratory smoked fish. The carbohydrate content decreased to zero while the moisture content increased. Mucor had the most significant effect on protein (62.06 ±13.39) and carbohydrate (1.11±0.95) levels in infected fish. pH dropped below7.0 by the end of four weeks in Mucor infected fish and fat content was lowest (14.19±3.82) in A. fumigates infected fish. There was a significant difference (p>0.05) between the nutrient values in the control and infected fish. The microbial content and lower nutrient values of infected fish emphasize the need to ascertain the health and nutrient content of market sold fish. This will ensure that consumers receive optimum nourishment and avoid the likely health implications of consuming infected fish.

Keywords: Fish nutrient, smoked Clarias gariepinus, microflora, Jos markets