Comparative Study on Quality Attributes of Three Fish Species Smoke-Dried Using Rubber Wood (Hevea brassillensis) in Nigeria

Aim: To examine the organoleptic and microbial quality of three fish species namely African red snapper(Lutjanus agennes), Mullet (Mugil cephalus) and Catfish (Chrysichthys walkeri) smoke-dried using rubber wood (Hevea brassillensis).
Study Design: Factorial experiment laid in completely randomized design
Place and Duration: Fisheries Department University of Benin between August and September 2011.
Methodology: Fish samples were bought from Ogbe-Ijoh market in Warri Delta State. Smoking was carried out using rubber wood (Hevea brassillensis) in a traditional rectangular mud kiln (Chorkor) and stored on open benches in the laboratory at room temperature (28 ± 2ºC). Fish samples were assessed tri-weekly for moisture content and sensory attributes. Three anatomical parts of fish samples were also analyzed for bacteria load during the six weeks period of storage.
Results: There was a general decline in all sensory attributes during storage. Moisture content of the fish samples varied with storage time but was not significant (P≥0.05). The highest mean bacterial counts of 3.9 x 106, 1.4 x 106 and 2.4 x 106cfu/g was recorded in the gills, muscle and skin of Chrysichthys walkeri after six weeks of storage respectively. There were significant (P≤0.05) difference in the mean bacterial count in the three anatomical parts among the fish samples during storage. The predominant bacterial species isolated from the three different anatomical parts of the three fish samples during the six (6) weeks storage period were made up of seven (7) genera of bacteria: Proteus (30.1%), Pseudomonas (26.5%), Micrococcus sp(18.1%) Bacillus (9.6%), Staphylococcus (9.6%), Escherichia coli (4.8%) and Streptococcus sp (1.2%)
Conclusion: The study revealed that by the sixth week of storage all tested fish had an overall mean score of acceptability less than 6 (i.e. fair).Therefore, the fish were marginally acceptable based sensory and microbiological evaluation. This is an implication that could pose a serious health concern for consumers.