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

The dietary bioaccessibility of seven 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) the differential centrifugation method and (2) the 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 with the in vitro digestion method (e.g., 10% vs. 42% for 241Am), and (2) the cooking process (5 min at 200 °C) leads 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).