Development and Evaluation of Low Polycyclic Aromatic Hydrocarbons (PAHs) Improved Fish Smoking Kiln

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic pollutants which get into foods during smoking. This research was used to develop an improved smoking kiln and to determine its effects of the methods of smoking in reducing the level of PAHs of a locally consumed fish in Nigeria. The fish specie clarias gariepenus (catfish) was smoked with different methods. They are the firewood in open-fire fish smoking drum (FOSD), charcoal using improved fish smoking kiln (CISK) and gas using improved fish smoking kiln (GISK). The PAHs was determined using the Gas Chromatography (GC) coupled with flame ionization detector (FID). Comparison of the concentration of PAHs in smoked fish samples were investigated with the aim of determining the process that has reduced the concentration of the PAHs in the fish samples. The total values of PAHs have shown that the methods FOSD, CISK and GISK have PAHs level of 80.01µg/g, 20.95µg/g and 14.69µg/g respectively. Benzo(a)pyrene, which is highly carcinogenic and posses health risk was found only in FOSD to be 9.20µg/g, while it was not detected in CISK and GISK respectively. As for other PAHs, they were all detected in FOSD, while fluoranthene was exceptionally high in all the methods used as 22.08µg/g, 10.23µg/g and 5.04µg/g respectively. However, naphthalene, phenanthrene, anthracene, pyrene, chrysene, benzo(b)fluoranthrene, benzo(k)fluoranthrene, benzo(a)pyrene and benzo(g,h)perylene were not detected (ND) in the developed improved fish smoking kiln. The developed improved fish smoking kiln has been able to reduce the level of PAHs considerably and is therefore recommended.