Assessment of metal , metalloid and radionuclide bioaccessibility from mussels to 1 human consumers , using centrifugation and simulated digestion methods coupled 2 with radiotracer techniques 3 4

The dietary bioaccessibility of 7 elements (241 Am, Cd, Co, Cs, Mn, Se and Zn) in 25 the Mediterranean mussels Mytilus galloprovincialis (Lamarck, 1819) was assessed for human 26 consumers. In this respect we assessed and compared the proportion of elements associated with 27 the cellular cytosolic (" soluble ") fraction vs. the bioaccessible fraction derived, respectively, 28 from (1) differential centrifugation method and (2) simulated digestion method. Comparisons 29 were carried out on both raw and cooked mussels. Results showed that (1) the centrifugation 30 method systematically underestimated (up to a factor 4) element bioaccessibility in raw mussels 31 compared to the in vitro digestion method (e.g., 10 vs. 42% for 241 Am), and (2) the cooking 32 process (5 min at 200°C) lead to concentrating the elements in mussel tissues (e.g., by a factor 2 33 for Zn) and reducing their bioaccessibility. Overall, the simulated in vitro digestion method 34 appears as a powerful tool for seafood safety assessment and cooking could contribute in 35 reducing substantially the global trace element intake from mussel tissues (up to 65% for Cd and 36 Cs). 37 38 39 3 Statement (according to requirements indicated in " EES Instructions to Authors "). 43 44 Funding sources that supported the work described in the manuscript were from IAEA-MEL 45 regular budget. 46 47 The present work was mainly carried out using in vitro techniques; however it also involved the 48 use of marine bivalves. All experimental studies were conducted in accordance with national and 49 institutional guidelines for the protection of animal welfare.