Level of polycyclic aromatic hydrocarbons concentration in smoked catfish (Clarias gariepinus) using African mesquite tree (Prosopis africana) wood derivatives as fuel

Abstract

The use of wood for thermal processing of fish may enhance desirable organoleptic attributes but may also allow the promotion of undesirable chemical compounds such as polycyclic aromatic hydrocarbons. The study was conducted to compare the polycyclic aromatic hydrocarbons content of smoked African catfish (Clarias gariepinus) using the charcoal and firewood of the African mesquite tree (Prosopis africana). The total polycyclic aromatic hydrocarbons content, and the sum of the four new polycyclic aromatic hydrocarbons markers (PAH4) namely; benzo(a)pyrene, benzo(a)anthracene, chrysene and benzo(b)fluoranthene were determined in the smoked fish products. The study revealed that the total polycyclic aromatic hydrocarbon was higher in the fire wood sample (105.75±13.69μg/kg) as compared to the charcoal sample (74.78±6.45μg/kg). PAH4 content was also higher in the firewood sample (37.23±9.15μg/kg) as compared with the charcoal sample (24.58±2.77μg/kg). All the samples exceeded the maximum limits set by the European Commission for PAH4 and Benzo(a)pyrene levels in smoked fish products. Control measures such as reducing the smouldering temperature and time, discarding the outer layer of the smoked fish or the Hazard Analysis Critical Control Points (HACCP) may be applied during fish smoking to reduce the level of polycyclic aromatic hydrocarbons present in the smoked products.