Effective Removal of Cadmium from Fish Sauce Using Tannin

Fish sauce prepared from squid organs contains cadmium (Cd), which may be present at hazardous concentrations. In this study, we report a new, inexpensive, and acceptable method for removing Cd from fish sauce using tannin, which is an approved food additive in Japan. Decreases in Cd concentrations of 13-fold were observed (0.39-0.03 mg/100 mL) by incorporating the soluble Cd into a precipitate generated by tannin treatment. The total nitrogen content, free amino acid content, 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, and angiotensin I-converting enzyme inhibitory activity of the treated fish sauce were the same as those of the untreated fish sauce.