Dong Naihui, Xue Siyu, Guo Hui, Xiong Kexin, Lin Xinping, Liang Huipeng, Ji Chaofan, Huang Zhiguo, Zhang Sufang
National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China.
Liquor-Making Biotechnology and Application Key Laboratory of Sichuan Province, Sichuan University of Science & Engineering, Yibin 644005, China.
Foods. 2022 Mar 24;11(7):937. doi: 10.3390/foods11070937.
Ethyl carbamate (EC), classified as a Group 2A carcinogen, is most abundant in the fermented foods, such as Cachaca, Shaoxing wine, and Chinese liquor (baijiu). Although biodegradation can reduce its concentration, a high ethanol concentration and acidic environment often limit its degradation. In the present study, a novel ethyl carbamate hydrolase (ECH) with high specificity to EC was isolated from , and its enzymatic properties and EC degradability were investigated. ECH was immobilized to resist extreme environmental conditions, and the flavor substance changes were explored by gas chromatography-mass spectrometry (GC/MS). The specific enzymatic activity of ECH was 68.31 U/mg. Notably, ECH exhibited excellent thermal stability and tolerance to sodium chloride and high ethanol concentration (remaining at 40% activity in 60% (/) ethanol, 1 h). The treatment of immobilized ECH for 12 h decreased the EC concentration in liquor by 71.6 μg/L. Furthermore, the immobilized ECH exerted less effect on its activity and on the flavor substances, which could be easily filtrated during industrial production.
氨基甲酸乙酯（EC）被归类为2A类致癌物，在发酵食品如卡莎萨酒、绍兴酒和中国白酒（白酒）中含量最高。尽管生物降解可以降低其浓度，但高乙醇浓度和酸性环境常常限制其降解。在本研究中，从[具体来源未给出]中分离出一种对EC具有高特异性的新型氨基甲酸乙酯水解酶（ECH），并对其酶学性质和EC降解能力进行了研究。将ECH固定化以抵抗极端环境条件，并通过气相色谱 - 质谱联用（GC/MS）探究风味物质的变化。ECH的比酶活为68.31 U/mg。值得注意的是，ECH表现出优异的热稳定性以及对氯化钠和高乙醇浓度的耐受性（在60%（体积分数）乙醇中1小时后仍保留40%的活性）。固定化ECH处理12小时可使白酒中的EC浓度降低71.6 μg/L。此外，固定化ECH对其活性和风味物质的影响较小，在工业生产过程中易于过滤。
