白酒固态发酵过程中不同品种高粱原料对氨基甲酸乙酯形成的影响

Effects of Different Sorghum Cultivars on the Formation of Ethyl Carbamate in the Solid-state Fermentation Process of Chinese Liquor

摘要:

氨基甲酸乙酯（EC）是一种致癌物质，广泛存在于乙醇饮料中。为明确高粱原料对白酒固态发酵过程中EC形成的影响，从而为降低白酒中EC含量提供理论指导，通过模拟白酒固态发酵，分析了不同品种高粱原料发酵过程中EC及其前体物质的变化规律。结果表明，固态发酵过程中糯高粱S3对应的最终EC产量（4.27 mg/kg）高于粳高粱S1（4.06 mg/kg）和S2（4.21 mg/kg），且其EC平均形成速率是粳高粱S1（0.22 mg/kg/d）和S2（0.24 mg/kg/d）的1.6倍。对EC前体物质研究发现，瓜氨酸和尿素是高粱固态发酵过程中EC形成的主要前体物质，其中瓜氨酸可能对S1和S2发酵产EC的贡献较大，而尿素则对S3发酵产EC的贡献较大。此外，在整个固态发酵过程中，氰化物并未参与EC的形成。研究表明，不同品种高粱原料对固态发酵过程中产EC的影响差异显著，选择合适的高粱品种，控制高粱原料所带入的EC前体物质的含量，可有效控制白酒固态发酵过程中的EC含量。

Abstract:

Ethyl carbamate （EC） is a carcinogen which is widely found in alcoholic beverages. The changes of EC and its precursors in the solid-state fermentation process were explored to illustrate the effects of various sorghum cultivars on EC formation，which could provide a theoretical foundation to decrease the content of EC in Chinese liquor. The results showed that the final EC yield in waxy sorghum （S3） was 4.27 mg/kg and higher than that in non-waxy sorghum，which were 4.06 mg/kg for S1 and 4.21 mg/kg for S2，respectively. Moreover，the average accumulation rate of EC in S3 was 0.39 mg/kg/d which was 1.6 times as high as that in S1 （0.22 mg/kg/d） and S2 （0.24 mg/kg/d）. Citrulline and urea were found to be two major precursors of EC in the solid-state fermentation process，where citrulline mainly contributed to EC formation in S1 and S2，while urea gave more contribution in S3. In addition，cyanide was not involved in EC formation during the solid-state fermentation. This study indicated that the effects of different sorghum cultivars on EC formation were significantly different. The control of EC precursors by choosing appropriate sorghum cultivars could effectively reduce the final EC yield in Chinese liquor.