Effect of canned tuna fish processing steps on lead and cadmium contents of Iranian tuna fish

The contents of Pb and Cd in two species of Iranian tuna fish (yellowfin and skipjack), which were caught from the Persian Gulf and Oman Sea, and the effects of canning processing steps on their contents were assessed by electrothermal atomic absorption spectrometry. The results revealed that the levels of lead and cadmium throughout the processing steps in yellowfin were in range of 0.154 ± 0.019–0.441 ± 0.025 μg/g and 0.029 ± 0.002–0.084 ± 0.0005 μg/g, respectively. Pb and Cd concentrations from received fish to final product in skipjack were found to be in range of 0.072 ± 0.031–0.218 ± 0.031 μg/g and 0.016 ± 0.001–0.062 ± 0.002 μg/g, respectively. The limit of detection for lead and cadmium were 0.058 μg/g (11.6022 μg/l) and 0.0007 μg/g (0.1485 μg/l), respectively. Results from paired sample t-test analysis showed that defrosting, cooking, and sterilisation by autoclave would reduce the contents of lead and cadmium, considerably.