Natural occurrence of deoxynivalenol in soy sauces consumed in China

A total of 40 samples of domestic and imported soy sauces with the greatest diversity were investigated for the presence and contents of deoxynivalenol (DON) by using GC–MS after pre-column derivatisation. Results showed that 97.5% of samples investigated were contaminated with DON, and there was a remarkable variation in the DON contents across soy sauce samples. The average incidence rate of DON in domestic soy sauces was 97.1% (range 4.5–1245.6 μg/l, average value 141.5 μg/l), while for those imported from Japan was 100% (range 30.5–238.3 μg/l, average value 113.7 μg/l). Manufacturing process and quality grade were found to have significant influences on the levels of DON in soy sauces. Generally, domestic soy sauces produced with low salt solid state fermentation and with higher quality grade exhibited higher DON contents. The present results also indicated that the exposure to DON from the consumption of soy sauces is at a very low risk level.