Thus defrosting might significantly reduce the concentration of
lead and cadmium in canned tuna fish due to possible separation of
serum. Furthermore, it could be concluded that cooking and sterilisation
might decline the concentration of lead and cadmium in
tuna fish during processing. The reduction in metal contents of fish
during the heating process may be related to the decrease of protein
content and release of these metals with the loss of water as
free salts, possibly associated with soluble amino acids and uncoagulated
proteins