Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China.
Department of Agricultural and Food Sciences, Alma Mater Studiorum, University of Bologna, 47521 Cesena, Italy.
Molecules. 2019 Apr 15;24(8):1474. doi: 10.3390/molecules24081474.
The aim of this work was to clarify the formation of ethyl carbamate (EC) and its influence factors throughout the production process of Cantonese soy sauce. The results showed that EC was not detected in the -making and early fermentation stages, but started to be generated when pH of the decreased to about 4.9-at the same time, the levels of ethanol, urea and citrulline increased significantly. Most EC was formed during raw soy sauce hot extraction (40.6%) and sterilization (42.9%) stages. The EC content exhibited the highest correlation with ethanol throughout the whole production process (R = 0.97). The simulation soy sauce produced in laboratory led the same conclusion-moreover, the contents of EC, ethanol and citrulline were higher in soy sauce fermented at 30 °C than in soy sauce fermented at 15 °C. Extraction of raw soy sauce by squeezing contributed little to EC formation. Further research showed that citrulline and ethanol led to significant increases in EC levels in raw soy sauce upon heating. These results indicate that ethanol and citrulline are two critical precursors of EC and that EC is mainly formed during the heat treatment stage of soy sauce.
本工作旨在阐明广东酱油生产过程中氨基甲酸乙酯（EC）的形成及其影响因素。结果表明，-制作和早期发酵阶段未检出 EC，但当 pH 值降至约 4.9 时开始生成-同时，乙醇、尿素和瓜氨酸的水平显著升高。大多数 EC 是在生酱油热提取（40.6%）和灭菌（42.9%）阶段形成的。EC 含量与整个生产过程中的乙醇呈最高相关性（R = 0.97）。实验室模拟酱油得出了相同的结论-此外，在 30°C 发酵的酱油中，EC、乙醇和瓜氨酸的含量高于在 15°C 发酵的酱油。生酱油的压榨提取对 EC 的形成贡献很小。进一步的研究表明，在生酱油中，瓜氨酸和乙醇的加热会导致 EC 水平显著升高。这些结果表明，乙醇和瓜氨酸是 EC 的两个关键前体，EC 主要在酱油的热处理阶段形成。
