COMPARISON OF CHELATING ACTIVITY OF SOY-SAUCE AND FISH SAUCE PRODUCED IN ASIAN COUNTRIES

Sixteen soy sauces and 4 fish sauces produced in Asian countries were subjected to electrodialysis. Their nondialyzable fraction was determined for iron (II) chelating activity by HPLC using a gel permeation column equilibrated with 0.01 M acetate buffer (pH 4) containing 0.1 mM iron (II) sulfate. The Fe-complex of each sample was detected in melanoidin fractions and in uncolored fractions, and the characteristics of the sause sample were represented by the elution profiles of Fe-complex. The results show that the amount of iron chelated per ml of electrodialyzed soy sauce ranged from 0.11 to 1.95 mg, and that of the fish sauce ranged from 0.13 to 0.50 mg. The chelating activity of soy sauce was larger than that of fish sauce. The chelating activity of the sauces was not always correlated with the color intensity at 450 nm of the samples, since some iron complex appeared in uncolored fractions of HPLC analysis.