We have developed a new method for removal of Cd from fish
sauce using a combination of chelate resins that are approved as
food additives and the previously reported tannin method. This
combined method removed both liberated and protein-bound Cd
from fish sauce, and solved the limitations of tannin treatments.
The iminodiacetic acid type chelate resin (Diaion CR11) was more
suitable for the removal of Cd from fish sauce than the ethylene
diamine type (Diaion CR20). Accordingly, CR11 removed Cd more
effectively than CR20 in the column method. Moreover, Cd–CR11
binding was strongly inhibited by NaCl, although other fish sauce
components reduced this effect. Finally, chemical components
with nutritional value or known beneficial functions were retained
after tannin and chelate resin treatments. Thus, the present
method is safe and effective and has promising applications in fish
sauce factories