EFFECTS OF TRIMMING AND COOKING BY SEVERAL METHODS ON POLYCHLORINATED BIPHENYLS (PCB) RESIDUES IN BLUEFISH

Abstract
Bluefish were captured in the Atlantic Ocean near Long Island to study the effects of trimming and cooking on reduction of residues of polychlorinated biphenyls (PCBs). The mean concentration (standard error) of PCBs in the raw untrimmed fillets of the fish captured was 1.76 ± 0.17 ppm on a dry weight basis with range of 0.58 to 7.47. A direct relation between the concentration of PCBs in the raw fish fillets and their fresh weight showed a correlation coefficient of only 0.39. About twice the concentration of PCBs were found in the skins as compared to the dorsal and ventral sections of the raw fillets. Trimming the fillets resulted in a reduction in PCB residues averaging 59.4% with a further average reduction of 7.4% from baking, broiling, frying or poaching. There were no significant (p > 0.05) differences among the combined trimming and various cooking methods in the magnitude of reduction of PCB residues. The total quantities of PCBs found in the oil collected after baking, broiling or frying the fillets were less than could be accounted for as total cooking losses thus indicating that vaporization of PCBs during cooking may also occur.