Determination of ethyl carbamate in some fermented Korean foods and beverages

Ethyl carbamate has been associated with cancer for several decades. It is mainly found in fermented foods and beverages. In view of the importance of fermented foods in the Korean diet and the significant level of ethyl carbamate expected, we determined ethyl carbamate concentrations in some of the staple food items and estimated the daily intake for the Korean population. Ethyl carbamate in commercial samples of kimchi, soy sauce, vinegar, soybean paste, and alcoholic beverages were determined by gas chromatography-mass spectrometry/selective ion monitoring (GC-MS/SIM). Homemade soy sauce and kimchi were also analysed. The maximum ethyl carbamate concentrations observed were 73 mu g/kg in soy sauce, 7.9 mu g/kg in soybean paste, 2.5 mu g/l in vinegar, 16.2 mu g/kg in kimchi and 15.4 mu/l in Korean traditional alcoholic beverages. Combining these values with the average daily food intake data, we estimated that the maximum daily exposure of Korean population to ethyl carbamate is 2.8 mu g/day, which is not a negligible amount considering the 'virtually safe dose' derived by animal experiment ranges between 1.2 and 4.8 mu g/day. It would be desirable to closely monitor ethyl carbamate levels in Korean foods and to find ways to reduce the daily intake.     

影响SPE-GC/MS法检测发酵食品中氨基甲酸乙酯因素的研究

针对SPE-GC/MS法测定EC的主要影响因素,对萃取小柱类型、型号、洗脱剂用量及检测样品pH等萃取条件进行了优化。结果表明,采用氨基甲酸丙酯（PC）为内标和选择离子监控模式（SIM）,在30⁵00μg/L范围内具有满意的线性度（R2=0.9992）;常用的4种不同类型的萃取小柱中,硅藻土小柱的通用性较强;15mL二氯甲烷是最佳的洗脱剂用量;检测样品的pH调至7.0后,改善了检测的精度和准确度。优化后的方法在用于基质形态和性质不同样品验证实验的结果显示,该法具有准确度高和抗干扰能力强的特点,且所检测样品的RSD均在5%以下。      

发酵食品中氨基甲酸乙酯污染及其毒性研究进展

氨基甲酸乙酯(ethyl carbamate,EC)是在食品发酵过程中产生的一种化学污染物,广泛存在于发酵食品和酒精饮料中。对于啮齿类动物,氨基甲酸乙酯是一种多位点致癌物,可以导致动物发生肺癌、淋巴癌、肝癌和皮肤癌等疾病。国际癌症研究机构(IARC)已将其认定为2A级致癌物,鉴于其对人类具有潜在的致癌性,氨基甲酸乙酯污染已成为近年来国际社会高度关注的食品安全热点问题之一。本文总结了当前国内外氨基甲酸乙酯的研究现状,对其理化特性、代谢途径、毒性、在发酵食品中的污染情况及各国限量标准进行了综述。最后建议我国相关部门应积极开展氨基甲酸乙酯安全问题调查和研究,帮助企业改进生产工艺,建立国家限量标准,以利于与国际接轨,促进我国发酵食品相关工业长期健康发展。     

Development of easy and efficient methods for quantitative analysis of ethyl carbamate using GC-MS in various fermented foods

To develop more efficient quantitative analysis of ethylcarbamate in fermented food, the major disturbance was identified as diethyl succinate on GC-MS through matching with mass fragmentation pattern on mass library and comparison of retention time. And the clean-up method was developed based on the difference of partition coefficient between ethyl carbamate and diethyl succinate. Finally, a washing step was added with 1% dichloromethane in n-hexane on diatomaceous earth cartridge, and successfully applied to remove diethyl succinate from the matrix. The developed method showed acceptable recovery rate (69.5–88.4%) and limit of quantitation (1.0–1.2 ng/mL) on several fermented foods.     

Lactic acid bacteria in traditional fermented Chinese foods

Food fermentation is a widely practiced and ancient technology in China. Lactic acid bacteria (LAB) are involved in many fermentation processes of Chinese traditional foods, demonstrating their profound effects on improving food quality and food safety. This review article outlines the main types of LAB fermentation as well as their typical fermented foods such as koumiss, suan-tsai, stinky tofu and Chinese sausage. The roles of LAB and the reasons for their common presence are also discussed.     

Analysis and risk assessment of ethyl carbamate in various fermented foods

Ethyl carbamate (EC) was analyzed in fermented foods, comprising various matrices; subsequently, a risk assessment for EC was carried out. In total, 128 fermented foods were purchased from department stores and traditional markets in Korea. The samples comprised 55 lactic acid–fermented vegetable (kimchi), 53 fermented soybean paste (doenjang, gochujang, cheonggukjang, and ssamjang), 20 fermented fish products (jeotgal), 18 yoghurt, 37 bread, 12 cheese, and 23 vinegar samples. The level of EC in fermented soybean pastes ranged from not detectable to 240.2 ng g^?1. EC was not detected in kimchi, jeotgals, yoghurt, and cheese. Bread and vinegar contained EC up to 3.70 and 16.79 ng g^?1, respectively. The estimated daily intake and chronic daily intake of EC were 1.98 ng kg body weight (bw)^?1 day^?1, 1.50 ng kg bw^?1 day^?1, respectively. Excess cancer risk and margin of exposure of EC were 7.5 × 10^?8 and 151,515, respectively.     

Exposure assessment and risk characterisation of ethyl carbamate from Korean traditional fermented rice wine,Takju and Yakju

Ethyl carbamate is one of the most hazardous chemicals naturally occurring in food, and is present in alcoholic beverages. Korean traditional rice wine, Takju and Yakju, is frequently consumed in Korea, but there have been no studies characterising the risks of ethyl carbamate in these products. In order to assess and characterise the exposure risk of ethyl carbamate in Korean traditional rice wines, ethyl carbamate was investigated by means of GC-MS. The analytical methods were optimised and validated through determining linearity, detection limit, quantification limit, recovery and precision. A total of 283 traditional Korean rice wines, including 175 Takju and 108 Yakju samples, were analysed. Exposure assessment was performed by factoring in ethyl carbamate content, daily consumption and body weight. Daily exposures of ethyl carbamate were estimated for adults in four age groups, and risks of ethyl carbamate were characterised by the margin of exposure, which is more than 10 000. Based on this study, the risks of ethyl carbamate in Korean traditional rice wine were shown to be of low concern.     

发酵食品中氨基甲酸乙酯检测的研究进展

氨基甲酸乙酯为2A类的致癌物,在发酵食品中广泛存在,检测氨基甲酸乙酯的残留对食品安全具有重要意义。介绍了检测发酵食品中氨基甲酸乙酯含量的预处理方法,对气相色谱、液相色谱、傅里叶变换红外光谱、核磁共振分光检定法和时间分辨荧光免疫分析方法等在氨基甲酸乙酯残留检测中的应用情况作一综述,并展望了未来的发展前景和研究方向。     

饮料酒中氨基甲酸乙酯检测方法研究进展

氨基甲酸乙酯存在于黄酒、葡萄酒等酒精类饮料中,对人体具有潜在致癌作用,已被国际癌症研究机构确定为2A级致癌物。随着我国居民生活水平不断提高,酒精类饮料的消费量日趋上升,导致人均氨基甲酸乙酯的暴露量也日益上升,但是我国目前仍未对饮料酒中氨基甲酸乙酯做出限量标准。自从1985年加拿大报道了酒中有较高的氨基甲酸乙酯含量后其检测方法备受兲注,本文介绍了用于检测饮料酒中氨基甲酸乙酯的常用方法如气相色谱法、气相色谱质谱联用法、高效液相色谱法、薄层色谱法、傅里叶变换近红外光谱法等,幵简述了其特点及应用。以期能为饮料酒中氨基甲酸乙酯检测方法的发展提供参考,同时,我国应尽快对饮料酒中氨基甲酸乙酯做出限量标准以保障饮料酒行业快速、健康发展,保护我国居民健康。     

发酵食品中氨基甲酸乙酯污染状况调查与分析

采用液液萃取和基质固相分散的样品前处理技术,应用气相色谱-串联质谱的检测方法对发酵食品中氨基甲酸乙酯(ethyl carbamate,EC)的污染状况进行调查和分析,共检测发酵食品437批次,其中EC阳性样品343批次,阳性率为78.49%,阳性率最高的是果酒100%,其次是酱油98.17%、醋86.67%和黄酒78.38%,最低的是啤酒,为未检出。饮料酒中EC平均值最高的是黄酒90.4μg/L,其次为保健酒62.9μg/L,最低为葡萄酒,为7.6μg/L,调味品中酱油和醋EC平均值分别为84.1μg/kg和76.2μg/kg,焙烤食品中面包EC平均值24.3μg/kg。研究结果表明,黄酒、酱油和醋中EC的阳性率、平均值相对较高,在今后的研究和监测中需要重点关注。     

发酵酒中氨基甲酸乙酯形成的代谢途径及控制

氨基甲酸乙酯是一种存在于发酵酒中的致癌物.发酵酒中氨基甲酸乙酯主要由酵母降解精氨酸产生的尿素和乳酸菌降解精氨酸产生的瓜氨酸与乙醇自发反应形成.该文综述了发酵酒中氨基甲酸乙酯形成的代谢途径并探讨了降低发酵酒中氨基甲酸乙酯含量的控制策略.     

发酵食品中氨基甲酸乙酯的形成途径及消减策略研究进展

氨基甲酸乙酯(ethyl carbamate, EC)主要存在于发酵食品中,是一种具有遗传毒性和致癌性的化合物,长期摄入会显著增加各种癌症的发病率。研究表明,氨基甲酸乙酯形成途径主要是由相关前体物质在食品发酵或贮藏过程中反应生成;其前体物质主要有尿素、瓜氨酸、氨甲酰磷酸、焦碳酸二乙酯、氰化物等,这些主要的氨基甲酸乙酯前体物通常是由酿酒酵母或乳酸菌的精氨酸代谢伴随着发酵过程而产生的。由于氨基甲酸乙酯对人类身体健康的潜在威胁,减少发酵食品中的氨基甲酸乙酯显得尤为必要。本文针对发酵食品中氨基甲酸乙酯的形成途径,从物理法、化学法、酶法以及代谢过程法系统综述了发酵食品中氨基甲酸乙酯的消减策略,可为提高我国发酵食品的安全生产提供理论依据。     

Investigation of ethyl carbamate levels in some fermented foods and alcoholic beverages

An analytical procedure has been developed for the determination of trace amounts of ethyl carbamate in fermented foodstuffs and alcoholic beverages. Concentrations were generally below the 1-5 micrograms/kg detection limit in bread, cheese, yoghurt, beer, gin and vodka. Higher concentrations were found in the other alcoholic beverages examined, which included whisky, fruit brandy, liqueur, wine, sherry and port.     

食品化学检验方法的确认

为提高食品卫生理化检验工作的质量，对化学分析方法的操作特性及分析方法确认的基本准则和具体要求进行了综述，对食品卫生监督检验工作中分析方法的确认提出了建议。     

中国5省市居民黄酒中氨基甲酸乙酯的风险评估

目的对中国东南地区5省市居民黄酒中氨基甲酸乙酯暴露的健康风险进行评估。方法利用2002年中国居民营养与健康状况调查5省市18岁及以上人群黄酒消费量数据,以及2010、2011年在5省市采集黄酒样品的检测结果,采用简单分布膳食暴露评估方法对人群经黄酒摄入氨基甲酸乙酯进行估计,并对造成的健康风险进行评估。结果 5省市黄酒中氨基甲酸乙酯的平均含量为0.103 mg/kg,最大值为0.498 mg/kg。18岁以上人群黄酒氨基甲酸乙酯平均暴露量为13.4 ng/kg BW,暴露限值为22 388。黄酒饮酒者氨基甲酸乙酯平均暴露量为427.8 ng/kg BW,暴露限值为701。结论 18岁及以上全部人群黄酒氨基甲酸乙酯暴露的健康风险较低,但在黄酒饮酒者中存在较高健康风险。     

同位素内标-超高效液相色谱-高分辨质谱法测定酒醅中氨基甲酸乙酯

目的：建立同位素内标法结合超高效液相色谱串联高分辨质谱检测酒醅中氨基甲酸乙酯(ethyl carbamate, EC)含量的分析方法。方法：酒醅样品经超纯水超声提取离心过滤后,以0.1%甲酸水溶液-甲醇溶液为流动相梯度洗脱,通过Hypersil GOLD 色谱柱分离目标物,在电喷雾正离子模式下采用一级全扫模式内标法定量分析。结果：同位素内标定量法能有效补偿样品中基质干扰,EC含量在4～300 μg/L浓度范围内线性关系良好(R_²>0.9993),定量限(LOQ)为2.50 μg/L,检出限(LOD)为1.50 μg/L。实际样品加标回收率在85.17%～97.40%范围之间,相对标准偏差(RSD)为1.12 %～4.11 %。结论：该方法线性、准确度和精密度均满足GB/T 27417—2017《化学分析方法确认和验证指南》的要求,适用于酒醅中EC的分析检测。     

发酵食品中多种防腐剂检测方法的建立

该实验建立了高效液相色谱法同时测定苯乳酸、苯甲酸、山梨酸的方法。在以C18柱为分离柱,流动相为甲醇-0.020 mol/L乙酸铵（20∶80,V/V）,色谱柱温为25 ℃,流速为1.0 mL/min,检测波长为220 nm条件下,12 min内可实现苯乳酸、苯甲酸、山梨酸的分离。该方法在0.25～50.00 mg/L范围内具有良好的线性关系（相关系数R2＞0.998）,检出限（LOD）＜50.00 ng/mL,回收率为96.93%～118.42%,精密度试验结果相对标准偏差（RSD）为0.39%～6.21%。该方法操作简便、结果准确度高,可用于发酵食品中苯乳酸、苯甲酸和山梨酸的同时分析检测。     

Retrospective trends and current status of ethyl carbamate in German stone-fruit spirits

Ethyl carbamate (urethane, C₂H₅OCONH₂) is a known genotoxic carcinogen of widespread occurrence in fermented food and beverages with highest concentrations found in stone-fruit spirits. Between 1986 and 2004, 631 cherry, plum or mirabelle (yellow plum) spirits were analysed for ethyl carbamate using gas chromatography in combination with mass spectrometry after extrelut extraction. The ethyl carbamate concentration of the samples ranged between 0.01 mg l^-1 and 18 mg l^-1 (mean 1.4 mg l^-1). After exposure of the samples to UV light, significantly (p = 0.001) higher concentrations between 0.01 mg l^-1 and 26 mg l^-1 (mean 2.3 mg l^-1) were found. The ethyl carbamate concentration increased on average by 1.3 mg l^-1. A linear correlation between the year of sampling and ethyl carbamate concentration showed a statistically significant but very slight decrease (R = -0.10, p = 0.024). However, if only samples which officially were non-compliant were considered exceeding the upper limit of 0.4 mg l^-1 more than twice, a significant reduction (R = -0.56, p = 0.018) of the quota was evident. This shows that measures to reduce ethyl carbamate were successfully introduced in many distilleries. However, nearly 20 years after the first warnings about ethyl carbamate in spirit drinks, the problem persists especially in products derived from small distilleries. During experimental production of stone-fruit spirits using state-of-the-art technologies, it was shown that the occurrence of ethyl carbamate in stone fruit spirits is preventable. Even for small distilleries, simple possibilities like destoning exist to minimize the ethyl carbamate content.     

固相萃取-气相色谱-质谱法测定腐乳中氨基甲酸乙酯

目的建立一种固相萃取-气相色谱-质谱法(solid phase extraction-gas chromatography-mass spectrometry,SPE-GC-MS)检测腐乳中氨基甲酸乙酯的方法。方法利用D5-氨基甲酸乙酯同位素做内标物,样品用20%乙醇水溶液提取后,利用碱性硅藻土固相萃取柱净化,洗脱液经浓缩后用气相色谱-质谱法测定样品中氨基甲酸乙酯。结果该方法的加标回收率在88.8%~104.1%之间,相对标准偏差(relative standard deviation,RSD)小于10%,定量限为2.0μg/kg(S/N=10)。结论该方法提取效果好,可以有效去除干扰物质,检测灵敏度、准确度均满足检测工作要求。     

酿造酒中氨基甲酸乙酯控制的研究进展及对中国黄酒的借鉴

人体潜在致癌物-氨基甲酸乙酯（EC）是发酵酒精饮料（中国黄酒、葡萄酒、日本清酒等）酿造过程中伴随产生的副产物,不少国家对市场上各酒种中EC的含量制定了严格的限定标准。黄酒是我国特有传统酒种,当前黄酒中EC含量较高的现状已成为制约我国黄酒业发展尤其是国际化发展的瓶颈之一。本文就近些年国内外已报道的酿造酒中EC形成机理及控制策略研究的现状进行综述,并分析给予中国黄酒的借鉴作用,以期为解决中国黄酒的EC问题提供思路。