Occurrence of polychlorinated biphenyl residues in frozen muscle and frozen cooked loin of tuna (Katsuwonus pelamis)

Abstract

In order to identify a possible contamination by polychlorinated biphenyls (PCBs) and to evaluate the effect of the fish processing upon the residue contents of these compounds, 41 PCBs congeners were investigated in samples of frozen muscle and frozen cooked loin of tuna (Katsuwonus pelamis) from a fishery industry of Rio Grande/RS. Samples were extracted by Sohxlet, purified, fractionated and analyzed by gas chromatography with electron capture detector (GC-ECD). The PCBs concentrations in the analyzed samples ranged from 0.58 to 95 ng.g-1 (lipid weight). Although the results indicated the occurrence of PCBs congeners in all of tuna (Katsuwonus pelamis) samples, the contents were lower than the maximum value established by the European Union legislation for products from animal origin (up to 200 ng.g-1 lipid weight). In Brazil, the maximum permitted contents is 3000 ng.g-1 (lipid weight). The comparison among the detected amounts evidenced that the processed samples showed higher concentrations of PCBs; thus, the fish processing might be a factor which cause effect on the final contaminant concentration.