COMPARATIVE DRYING PROFILES AND POLYCYCLIC AROMATIC HYDROCARBON CONTENT OF CATFISH SMOKE-DRIED USING TRADITIONAL DRUM AND NEWLY CONSTRUCTED ECO FISH KILN

Abstract

Smoke-drying is the most popular processing technology utilized in increasing the shelf-life of fresh fish in nigeria. the deposit of polycyclic aromatic hydrocarbons (pahs) on the fish during smoke-drying process however has potential health implications when consumed. this study investigated the drying profiles and levels of pahs in catfish (clarias gariepinus) samples smoke-dried using traditional drum kiln (tdk) and a newly constructed ecologically friendly fish kiln (efk) fitted with different sizes of smoke filters (0.1 cm in two layers, 0.3 cm in two layers and 0.3 cm in four layers). the drying profile was obtained by plotting the average weight and moisture loss of the smoke-drying catfish against time while the extraction method for pah samples was conducted according to american society for testing and materials astm d3328 and astm 3415 methods. the results showed that the drying profile of efk fitted with 0.3cm smoke filter in two layers gave the best output on the quality of drying in terms of percentage weight loss over time. levels of benzo(a)pyrene and pah4 [benzo(a)pyrene, benzo(a)anthracene, benzo(b)fluoranthene and chrysene] of smoke-dried catfish using tdk were higher than levels using efk fitted with 0.1 and 0.3 cm smoke filters although all were lower than maximum european union level of 0.005 and 0.03 mg/kg respectively. the study showed that maintaining temperatures between 60 - 80⁰ c produced smoke-dried catfish products considered safe for human consumption when both kilns were used with  best results from efk fitted with  two layers of o.3 cm smoke filters.