Degradation of ethyl carbamate in strong-flavor Baijiu by the microbial combination culture

Ethyl carbamate (EC) is a potentially carcinogenic compound in Chinese Baijiu that can be reduced by adjusting the starter cultures. This work studied the effects of Bacillus amyloliquefaciens J10 and Wickerhamomyces anomalus M11 on EC and its precursors in Chinese Baijiu fermentation. Efficient strains were obtained, and the optimal mixed culture method was established for EC degradation via the comparative analysis of the enzyme activity and the EC concentrations in these strains. When Bacillus amyloliquefaciens J10 and Wickerhamomyces anomalus M11 were inoculated at a ratio of 1.5:1 into the Baijiu fermentation with additional EC, the EC concentration was reduced by up to 50.5%. During simulated fermentation, this method degraded 38.05% of the EC and improved the flavor of the liquor. In conclusion, this study found an effective method to reduce the EC content in Chinese strong-flavor liquor, providing a new reference for safely producing this product.