Changes in total PCB content in selected fish products during hot- and cold smoking

Background. Stability and high bioaccumulation coefficients of polychlorinated biphenyls (PCB) in aqueous organisms may constitute a health hazard for their consumers (it is really the potential toxicity of PCBs that determine their hazard—not stability). As the fish are mostly eaten in the form of processed products, the influence of technological processes and different methods of cooking on changes in the levels of toxic compounds in final products is of great importance and may be helpful for appropriate processing. Since smoked fish products are in great demand in Poland, the goal of this study was to determine changes in total PCB content in herring fillets during hot smoking and in hot and cold smoked mackerel fillets. Materials and methods. Herring fillets were hot smoked under industrial conditions, whereas mackerel fillets were cold- and hot smoked. Analyses were carried out using a capillary gas chromatograph coupled with a mass spectrometer GC-MS (HP 6890/5973) with a HP-5 column. Results. The hot smoking process affected the loss of total PCB content in mackerel and herring fillets, with its highest value in the first hour of partial drying. The main factor determining the changes in the content of these compounds in wet matter and lipids was their escape in co-distillation with water vapour. The increase of their content, in the final stage of hot smoking and during the whole cold smoking process, was caused by contamination of fish fillets with polychlorinated biphenyls present in the curing smoke. Conclusion. From the toxicological point of view the process of hot smoking, is much healthier for people because it causes the reduction of total PCB content in final smoked products. Cold smoked mackerel is much more popular on the Polish market for its stronger taste and aromatic smell. However, lengthy exposure to smoke in low temperature increased the total PCB content in cold smoked fish. The consumption of these products should be limited based on these results.