Quality and Safety Assessment of Traditional Smoked Fish from Lagos State, Nigeria

Abstract

This study was carried out to investigate the quality and safety status of traditional smoked of fish from Lagos State, Nigeria. Fresh fish samples (100) (Silver catfish, Spotted tilapia, Bonga shad, Nigerian tongue sole and Guinea barracuda) were collected from twenty fishing/processing centres from Badagry and Epe Local Government Areas of Lagos State, Nigeria. The samples were divided into two batches, one batch was smoked with drum kiln and the second batch was taken to the laboratory for analysis. Laboratory analyses were carried out on the two batches for: proximate (protein, fat, moisture, crude fibre, and ash), quality indices (peroxide value PV, thiobarbituric acid TBA, total nitrogen base-nitrogen TVB-N, trimethylamine acid TMA, free fatty acid FFA and pH), heavy metals and microbiological (coliform, fuugi, listeria monocytogenes salmonella paratyphi and staphylococcus aureus). The results of the proximate, quality and microbiological analyses revealed that there was significant variations (p<0.05). T he mean m oisture content of fresh fish samples ranged from 73.48% – 75.94% and that of smoked fish samples ranged from 11.86% - 13.41% . The mean protein content of fresh fish samples ranged from 15.18% – 17.96% and that of smoked fish samples ranged from 54.80% – 59.35%. An inverse relationship was observed between the moisture and protein content in the smoked fish samples. The study showed that smoking affects quality and significantly (P<0.05) reduced the moisture content of smoked fish and the quality indices such as FFA, TBA and PV. The study concluded that the levels of the four heavy metals investigated in the fish samples are generally below the maximum permissible levels set by World Health Organization for Pb (0.3 ppm); Cd (0.2 ppm), Hg (0.2 ppm) and Cr (0.5 ppm) and hence pose no risk to smoked fish consumers . However, samples of smoked fish showed presence of Listeria monocytogenes which may constitute a threat to public health.