Effect of Extraction Methods on the Polycyclic Aromatic Hydrocarbons Content Smoked Catfish Species in Niger State of Nigeria

Abstract

Catfish species collected from three different fishing zones namely; Katcha/Baro, Shiroro/Sarkin-Pawa and Wushishi/Gwarjiko/Zungeru areas of Niger state smoked with the traditional kilns (the drum and the mud-type smoking kilns) were screened for their polycyclic aromatic hydrocarbons (PAHs) content using three different extraction methods namely; accelerated solvent, Soxhlet and solid-liquid and GC/MS. Results from the study showed that the PAHs content in the studied smoked Clarias gariepinus (Catfish), ranged between 0.75-2.25, 0.40-2.00 and 0.25-1.75μg/kg for the accelerated solvent Soxhlet and solid-liquid extraction method irrespective of zone, while the index of PAH contamination, benzo(a)pyrene range between 1.28-1.96, 0.4-1.62 and 0.25 -1.54 μg/kg for the accelerated solvent, Soxhlet and solid-liquid extraction method, respectively. Generally, the PAHs content in the studied smoked fish species from the various zones were comparable and ranged between 0.40-2.25μg/kg and were below the European Union’s recommended limit of 5μg/kg for carcinogenicity in smoked meat and fish products. The results also show that the accelerated solvent method was more efficient for the extraction of PAHs in the studied fish species than the Soxhlet and solid-liquid extraction method. The findings also revealed that the variation across zones may have been due to the type of smoking kilns used