Occurrence of chloropropanols in soy sauce and other foods in China between 2002 and 2004

A survey of chloropropanols in soy sauce and some selected foods in China is reported. Thirty-seven traditionally brewed soy sauce samples contained 3-MCPD below the EC maximum limit (ML) of 0.02 mg kg(-1) All soy sauce samples (629) from retailers contained levels of 3-MCPD ranging between <0.005 (LOQ) and 189 mg kg(-1) and only 12.2% had levels in excess of the Chinese ML of 1.0 mg kg-1 for acid hydrolyzed vegetable protein (acid HVP). This indicates that the necessary processing changes have been made to decrease levels of chloropropanols in soy sauce. 2-Monochloropropane-1,3-diol (2-MCPD), 1,3-dichloro-2-propanol (1,3-DCP) and 2,3-dichloro-l-propanol (2,3-DCP) were detected in 48.1 19.1 and 3.78% of the soy sauce samples, respectively; the highest levels being 20.3, 8.26 and 0.50 mg kg(-1) respectively. A good linear correlation was found between the amount of 3-MCPD and 2-MCPD, with the level of 3-MCPD being generally higher than that of other chloropropanols for the same soy sauce. Acid HVP contained 3-MCPD at a level of 0.010-117.7 mg kg(-1) (on a liquid basis) and 80% of samples contained levels exceeding 1.0 mg kg(-1). In some other foods investigated, relatively high levels of 3-MCPD were found in soy sauce powder, oyster sauce, beef products, instant noodle spices and health foods, ranging from 0.029 to 13.64 mg kg(-1). It is concluded that abnormal levels of 3-MCPD in soy sauce or other foods produced in China may result from acid hydrolysis or the addition of the contaminated acid HVP.