Photostability of Sodium Iron Ethylenediaminetetraacetic Acid (NaFeEDTA) in Stored Fish Sauce and Soy Sauce

Sodium iron ethylenediaminetetraacetic acid (NaFeEDTA) has been suggested as a fortification compound for fish sauce and soy sauce. Its susceptibility to photodegradation in aqueous solutions however is a potential disadvantage. We determined the photostability of NaFeEDTA in fish and soy sauce stored under well‐defined conditions. No degradation of NaFeEDTA was observed during storage of fortified soy sauce. Losses of up to 35% NaFeEDTA, however, occurred within 2 to 6 wk in fortified fish sauce stored in clear bottles exposed to direct sunlight. Losses were prevented by storage in amber bottles or by storing the clear bottles under indirect sunlight or in the dark.