Polycyclic aromatic hydrocarbon and microbial load of naturally preserved smoked African mud catfish Clarias gariepinus (Burchell, 1822)

Abstract

Polycyclic Aromatic Hydrocarbon (PAH) and microbial load of naturally preserved smoked African mud catfish ( Clarias gariepinus Burchell, 1822) were examined. The experimental design was Complete Randomized Design (CRD) with the treatments been the variously preserved C. gariepinus catfish (garlic, ginger, garlic-ginger homogenate preserved and the control without spices). PAH and the microbial load were determined using standard experimental procedures. All PAH values were within internationally recommend value for human consumption, the aerobic mesophilic counts of unpreserved smoked catfish was significantly higher (p < 0.05) than other preserved smoked C. gariepinus (2.51 ± 0.01- 8.98 ± 0.02 log cfu/g); while garlic-ginger preserved smoked catfish product had the lowest aerobic mesophilic counts (2.48 ± 0.01-8.92 ± 0.01 log cfu/g) during the period of the experiment. Similar trends were observed in the mould fungal, Staphylococcal , coliform, Salmonella and Shigella counts . However, Staphylococcal counts, coliform count and Salmonella and Shigella counts were not detected in the samples at the onset of the experiment. The preserved smoked fish are good and safe for human consumptions when stored at ambient temperatures (25-36 o C) for 56 days. The combination of garlic and ginger provide a much stronger antibiotic effect than the individual ingredients.