Changes in heavy metals (arsenic, cadmium and mercury) contents in seafoods during cooking processes

Abstract

The aim of this study was to determine the effect of cooking on changes in arsenic, cadmium, and mercury concentrations in boiled and baked seafoods. Fish, like Jack mackerel (Trachurus murphyi Nichols, 1920) and black cusk-eel (Genypterus maculatus Tschudi, 1846), and shellfish, like clam (Prototha cathaca Molina, 1782), common mussel (Mytilus chilensis Hupé 1854) and Magellan mussel (Aulacomya atra Molina, 1782) were selected for the study. Both cooking processes caused a significant reduction in the arsenic content found in three of the fresh samples; in common mussel and black cusk-eel, arsenic concentrations showed no significant changes (p < 0.05). Similarly, cadmium content was also reduced in three of the five analysed seafoods, with common mussels and clam showing no significant changes in cadmium contents. In terms of mercury concentration no statistically significant difference between fresh and cooked fish samples was observed, which showed that mercury is a particular health risk due to the formation of methylmercury that is not solubilised during cooking. It was found that the cooking processes, such as baking and boiling, do have a significant effect on the heavy metal content of seafoods, but the extent of the reduction would depend on the particular seafood and heavy metal analysed.