Effect of Different Cooking Methods on Ethyl Carbamate in Soy Sauce

Abstract

Purpose: This study measured the ethyl carbamate (EC) content in commercial and home-made soy sauce and examined the effects of cooking methods, such as boiling and pan-frying, on the EC content. Methods: A total of 20 soy sauce samples including 14 home-made and 6 commercial products were analyzed according to the AOAC official method with some modifications. To simulate conventional boiling, soy sauce containing EC (14.59 µg/kg) was heated to 100ºC for four different times: 10, 20, 30, or 40 min. Pan-frying was conducted for 4 min at 170ºC. Results: EC was not detected in any of the homemade samples, whereas it was found in the commercial samples, ranging from 2.51 to 14.59 µg/kg. The concentrations of EC increased gradually with increasing boiling from 14.59 to 26.54 µg/kg, whereas pan-frying did not affect the EC level in soy sauce. Conclusion: These results indicate that EC is formed by a reaction between the EC precursors during boiling, suggesting that the cooking method of each food should be considered when estimating the dietary exposure to EC.