Assessment of metal, metalloid and radionuclide bioaccessibility from mussels to human consumers, using centrifugation and simulated digestion methods coupled with radiotracer techniques

International audienceThe dietary bioaccessibility of 7 elements (241Am, Cd, Co, Cs, Mn, Se and Zn) in the Mediterranean mussels Mytilus galloprovincialis (Lamarck, 1819) was assessed for human consumers. In this respect we assessed and compared the proportion of elements associated with the cellular cytosolic (“soluble”) fraction vs. the bioaccessible fraction derived, respectively, from (1) differential centrifugation method and (2) simulated digestion method. Comparisons were carried out on both raw and cooked mussels. Results showed that (1) the centrifugation method systematically underestimated (up to a factor 4) element bioaccessibility in raw mussels compared to the in vitro digestion method (e.g., 10 vs. 42% for 241Am), and (2) the cooking process (5 min at 200°C) lead to concentrating the elements in mussel tissues (e.g., by a factor 2 for Zn) and reducing their bioaccessibility. Overall, the simulated in vitro digestion method appears as a powerful tool for seafood safety assessment and cooking could contribute in reducing substantially the global trace element intake from mussel tissues (up to 65% for Cd and Cs)