Effect of Smoking Methods on Quality and Safety of Traditional Smoked Fish from Lagos State, Nigeria

Abstract

ABSTRACTThis study was carried out to assess the effect of smoking methods on quality and safety of traditional smoked of fish from Lagos State, Nigeria. Five types of fresh fish (40) samples each were obtained from 20 different fish processing centers. The fresh fish samples were divided into two batches. The first batch was smoked with drum kiln and second batch was smoked with convective kiln. Laboratory analyses were carried out on the two batches for proximate, rancidity indices (PV, TBA, TVBN, TMA, and pH), heavy metals and microbiological (coliform, fungi, Listeria monocytogenes, Salmonella paratyphi, and Staphylococcus aureus). The results revealed that the mean MC of fresh fish samples ranged from 73.48%–75.94% and that of drum-smoked fish samples ranged from 11.86%–13.41% and 8.56%–9.36% for convective smoked fish samples. The mean PC of fresh fish samples ranged from 15.18%–17.96% and that of drum-smoked fish samples ranged from 54.80%–59.35% and 57.45%–66.23% for convective-smoked fish samples. The results of the proximate, quality, and microbiological analyses revealed that there was significant variations (p < 0.05) due to smoking methods. The study showed that the levels of the four heavy metals investigated in the fish samples are generally below the maximum permissible levels set by WHO 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. The study concluded that traditional drum-smoked fish needs further cooking or heat treatment before it can be included in the menu, as non-heat treatment may pose higher microbiological risks to the consumers due to the presence of Listeria monocytogenes in some of the traditional drum-smoked fish samples which may constitute a threat to public health.