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Ethyl carbamate (EC) is carcinogenic, and, in China, oral intake of EC mainly occurs as a result of the consumption of alcoholic beverages. To obtain the latest EC intake and risk analysis results for the general population in China, the China National Center for Food Safety Risk Assessment (CFSA) conducted the sixth total diet study (TDS) as a platform to analyze EC contents and exposure due to the intake of alcoholic beverages. A total of 100 sites in 24 provinces were involved in the collection and preparation of alcohol mixture samples for the sixth TDS. There were 261 different types of alcohol collected across the country, based on local dietary menus and consumption survey results. Ultimately, each province prepared a mixed sample by mixing their respective samples according to the percentage of local consumption. The EC levels of these twenty-four mixed samples were determined using our well-validated gas chromatography-mass spectrometry (GC-MS) method. The values ranged from 1.0 μg/kg to 33.8 μg/kg, with 10.1 μg/kg being the mean. China's EC daily intake ranged from 0.001 ng/kg bw/d to 24.56 ng/kg bw/d, with a mean of 3.23 ng/kg bw/d. According to the margin of exposure (MOE), virtually safe dose (VSD), and T25 risk assessments of the carcinogenicity of EC, the mean lifetime cancer risk for the Chinese population was 9.8 × 104, 1.5 × 10−7, and 8.6 × 10−8, respectively. These data show that the carcinogenicity of EC in the general Chinese population due to alcoholic intake is essentially minimal. [ABSTRACT FROM AUTHOR]

Baijiu is a popular alcoholic beverage with a long history in China. However, the widespread presence of the ethyl carbamate (EC) carcinogen has raised many food safety concerns. To date, the main precursors of EC and its formation process have not been determined, resulting in difficulty controlling EC in Baijiu. In this study, the main precursors of EC are identified as urea and cyanide during the process of brewing for different flavors of Baijiu, while the dominant stage in which EC formation occurs is during the process of distillation rather than fermentation. In addition, the effects of temperature, pH value, alcohol concentration and metal ions on the formation of EC are confirmed. In the following study, the main precursor of EC is identified as cyanide during the process of distillation, and a combination of optimizing the distillation device and adding copper wire is proposed. Furthermore, the effect of this novel strategy is examined in gaseous reactions between cyanide and ethanol, reducing the concentration of EC by 74.0%. Finally, the feasibility of this strategy is verified in simulated distillations of fermented grains, reducing the formation of EC by 33.7–50.2%. This strategy has great application potential in industrial production. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Rubus chingii Hu is a widely cultivated fruit in China and has declared multiple bioactivities including antioxidative activity. Ethyl carbamate (EC), mostly found in fermented food and alcoholic beverages, is a recognized human carcinogen, and researchers have proposed the correlation between oxidative stress and its toxicity. This study acquired the polysaccharide from R. chingii (RP) and explored its effect on EC‐induced cytotoxicity using Caco‐2 cells as the cell model. RESULTS: Results showed that RP exhibited protection against EC‐induced toxicity by repairing redox imbalance as indicative of mitigated mitochondrial membrane potential collapse, attenuated reactive oxygen species overproduction, and impeded glutathione depletion. Moreover, the structural features of RP were characterized and revealed that it was mainly constituted by galacturonic acid and arabinose, with an average molecular weight of 7.039 × 105 g mol−1. CONCLUSION: Overall, our results provided a new approach dealing with the toxicity caused by EC from the perspective of oxidative stress and described a new potential healthy value of R. chingii Hu, which could contribute to the development of a promising dietary supplement and functional food. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Ethyl carbamate (EC) is a genotoxic and carcinogenic compound that is also a by-product of fermented foods (bread, sour milk, soy cheese, etc.) and alcoholic beverages (wine, sake, distilled liquor, etc.). Studies have showed that ethyl carbamate is ingested by humans primarily through the consumption of alcoholic beverages. Many countries have thus established EC limits for alcoholic beverages. Chinese liquor (Baijiu) is a traditional and unique distilled liquor, which has a huge consumption in China due to its excellent color, flavor, and taste. Therefore, the control of EC in Chinese liquor is of great significance. This review summarized for the first time the progress in presence level, analysis method, formation mechanism, and elimination strategy of EC of Chinese liquor in recent decades. Key points: • GC-MS and HPLC are the main methods to quantify EC in Chinese liquor. • EC is formed in the fermentation, distillation, and storage stage. • EC content can be reduced from raw material, microorganism, and production process. [ABSTRACT FROM AUTHOR]

Summary: Wine ageing is of great importance to the quality and organoleptic properties of Huangjiu. The aim of the present work was to investigate the effect of ageing temperature on the content changes in ethyl carbamate (EC) and its precursors including citrulline, arginine, ornithine and urea in Hakka Huangjiu. Aroma compound changes were also detected using headspace solid‐phase microextraction coupled with gas chromatography spectrometry. Results indicated that with the increase in ageing temperature, citrulline and EC concentrations increased, whereas arginine and ornithine concentrations decreased. Urea was decreased slightly from 4 to 20 °C while increased at 37 °C. Pearson test demonstrated that ageing temperature had significant correlation with EC and arginine. The concentrations of aroma compounds, especially esters, alcohols, acids and heterocyclic compounds were different in different ageing temperatures. Ageing temperature of Hakka Huangjiu was suggested setting in a lower temperature as for strictly controlling contents of urea and citrulline, as well as EC. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Result of a survey of ethyl carbamate (EC) in beer was carried out by gas chromatography-mass spectrometry (GC/MS). 217 samples were purchased from supermarkets in five cities of China. The concentrations of EC ranged from n.d. to 19.6 μg/kg with an average level of 2.2 μg/kg, and positive rate was 95.4%. Mean in domestic beer (N = 142, incidence 97.3%) was 1.8 μg/kg, lower than the 2.9 μg/kg in imported beer (N = 75, incidence 94.4%). The result of domestic beer showed that EC level in canned beer (N = 73, mean = 1.5 μg/kg) was lower than that in bottled beer (N = 69, mean = 2.1 μg/kg). Additionally, EC level of beer from different countries was varied. Furthermore, a strong positive correlation of EC content in beer with alcohol content, storage time, temperature and light exposure was observed. [ABSTRACT FROM AUTHOR]

Most of the fermented alcoholic beverages, particularly Chinese rice wine, contain the potentially human carcinogenic compound ethyl carbamate (EC). As a major EC precursor in Chinese rice wine, urea in fermentations can be transported into the yeast cell by urea permease and finally metabolized by urea carboxylase and allophanate hydrolase in vivo. To eliminate EC in Chinese rice wines, the present study constructed high urea uptake yeast strains N1-D, N2-D and N-D, by introducing a strong promoter ( PGK1p) into the urea permease gene ( DUR3) of the industrial Chinese rice wine yeast N85, and by the restoration of the URA3 gene at the same time. With these self-cloned, high urea uptake strains, the urea and EC in the terminal Chinese rice wine samples were reduced to different extents. With two copies of overexpressed DUR3, the N-D strain could reduce the urea and the EC by 53.4 and 26.1%, respectively. No difference in fermentation characteristics was found between the engineered strains and the parental industrial yeast strain N85. These results could help to optimize the genetic manipulation strategy for EC elimination in Chinese rice wine production. Copyright © 2015 The Institute of Brewing & Distilling [ABSTRACT FROM AUTHOR]

Ethyl carbamate (EC) is a potential human carcinogen widely existing in fermented foods and alcoholic beverages. The solid-phase extraction (SPE) coupled to gas chromatography mass spectrometry is a widely-used method to determine EC levels, but the accuracy varies with sample matrix and the effects of operation parameters are rarely examined. In this study, the influence factors involved in EC determination were investigated using Chinese liquor as sample matrix, and the improved method was further applied. Three types of SPE columns, including diatomite, Florisil, and primary-secondary amine, were compared in extraction efficiency, and the diatomite column exhibited the highest extraction efficiency. The optimal volumes of elution solvents with diatomite column were 15 mL for 3-mL samples solution loaded. In addition, the alcoholic strength for EC determination should be diluted below 20% (v/v) to avoid the enhancement of matrix-induced chromatographic response. Moreover, the pH neutralization could help improve EC recovery and peak resolution, reducing interfering effects. Based on these results, the improved method showed that the limit of detection, the limit of quantification, and average recoveries were 1.10 μg/L, 3.65 μg/L, and 93.06%, respectively. To further elucidate the underlying factors related to EC accumulation, partial least square regression analysis was conducted, and the results suggested that EC levels had the closest relationship with alcoholic strength among the remaining precursors. [ABSTRACT FROM AUTHOR]

Ethyl carbamate is a well-known carcinogen and widely occurs in Chinese rice wine. To provide more clues to minimise ethyl carbamate accumulation, the levels of possible precursors of ethyl carbamate in Chinese rice wine were investigated by HPLC. Studies of the possible precursors of ethyl carbamate in Chinese raw rice wine with various additives and treatments indicated that significant amounts of urea can account for ethyl carbamate formation. It was also recognised that citrulline is another important precursor that significantly affects ethyl carbamate production during the boiling procedure used in the Chinese rice wine manufacturing process. Besides urea and citrulline, arginine was also found to be an indirect ethyl carbamate precursor due to its ability to form urea and citrulline by microorganism metabolism. [ABSTRACT FROM PUBLISHER]

To evaluate the potential public health risk of ethyl carbamate (EC), EC exposure from fermented foods and beverages for Hong Kong population was estimated. In 276 samples analysed, EC was detected (limit of detection (LOD) at 0.4 µg kg−1) in 202 samples (73%), with higher levels in fermented red bean curd (150–650 µg kg−1) and yellow wine (140–390 µg kg−1), while low or non-detected (ND) in preserved vegetables (ND–10 µg kg−1) and fermented tea (ND–15 µg kg−1). The estimated dietary exposure from all fermented foods and beverages was 8.27 ng kg−1 bw day−1, while exposure excluding alcoholic beverages was 5.42 ng kg−1 bw day−1, with calculated margins of exposure (MOEs) at 3.6 × 104 and 5.5 × 104 respectively. The risk of adverse health effects was low for the average population but higher (MOE of 103) for high consumers of alcoholic beverages especially habitual drinkers of alcoholic types with high EC contents. [ABSTRACT FROM PUBLISHER]

Ethyl carbamate (EC) in wine, grain spirits and wine sauce (145 samples) was analysed using solid-phase extraction and stable isotope dilution GC/MS. Samples were obtained from markets in eight areas (Shijiazhuang, Baoding, Handan, Qinhuangdao, Langfang, Zhangjiakou, Xingtai and Cangzhou) of Hebei Province, China. The method had a limit of detection of 2 µg kg-1, with recoveries varying from 95.7 to 102% and RSD ranging 2.3-5.6%. The average concentrations of ethyl carbamate in wines, grain spirits and wine sauce were 14.7 (<2.0-44.5) µg kg-1, 33.8 (2.9-129) µg kg-1 and 8.7 (<2.0-63.3) µg kg-1, respectively. The results led to the development of limit standards that can be used to predict the concentration of ethyl carbamate in Chinese fermented wines. [ABSTRACT FROM AUTHOR]

Ethyl carbamate (EC) is a naturally occurring component in the fermented products, especially the Chinese yellow rice wine. EC has been found showing a potential for carcinogenity and causing food safety problems. This study is to investigate the application of the existing HPLC-FLD method to the analysis of EC in Chinese yellow rice wine, and to validate it for EC analysis with high through-out and applicability in Chinese yellow rice wine sample. The parameters examined in this study were fully evaluated. Results indicated that good linearity was obtained with a correlation coefficient exceeding 0.9990, the limit of detection and quantification was 73.2 and 243.9 μg L−1, respectively. Recoveries ranged between 98.30% and 101.30%, and the precision of this method was lower than 5% (RSD). The method conducted in this work was successfully applied to determine EC concentration in Chinese yellow rice wine samples from different origins. The negative correlation between EC formation and urea level in yellow rice wine samples is evaluated with the developed HPLC-FLD method. [ABSTRACT FROM AUTHOR]

The exposure of a high gloss polyurethane aircraft topcoat system with polyurethane intermediate coating and epoxy primer to strong ultraviolet radiation in Lhasa, Tibet was studied by using scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflectance Fourier-transform infrared (ATR-FTIR), and X-ray photoelectron spectroscopy (XPS). Micro-flakes were found to form on the topcoat surface after exposure and the size and quantity of the flakes increased with the increase of the exposure time. The magnitude of micro-bulges and the topcoat roughness increased after a long exposure to sunlight. Flakes and micro-bulges resulted in the loss of the topcoat gloss. ATR-FTIR and XPS analysis indicated that chain scissions of the polyurea C==O group and the polyurethane C—O—C and CO—NH groups occurred, and the degradation products of NH and carbonyl groups formed due to the exposure. The breaking of the chemical structure of the polyurethane resulted in a decrease in its elasticity and in the adhesion of the flakes to its surface. [ABSTRACT FROM AUTHOR]

Since Baijiu, a traditionally distilled Chinese spirit, is widely consumed, the health risks of the ethyl carbamate (EC) content are of significant concern. To assess the EC content and evaluate dietary exposure risk to Chinese Baijiu, 2039 Baijiu samples, including 715 Strong-flavor Baijiu (SFB), 702 Jiang-flavor Baijiu (JFB), and 622 Light-flavor Baijiu (LFB), were collected from 16 provinces. The mean EC concentration was 62.26 μg/L, ranging from n.d. to 382.33 μg/L. Moreover, SFB exhibited higher EC content (113.94 μg/L) than JFB (58.10 μg/L) and LFB (12.02 μg/L). The EC content varied between different geographic areas and was especially evident between East China and other regions. Based on Baijiu consumption data, the daily exposure to EC was calculated as 40 ng/kg bw/day for regular consumers, while SFB drinkers displayed a higher intake (73.2 ng/kg bw/day). The margin of exposure (MOE) indicated that the EC in SFB and JFB posed various health risks, necessitating the development of stricter supervision while reducing consumption to regulate the EC level in SFB and JFB. In addition, this study identified safe drinking limits for consumers, recommending 0.46 L/month for SFB, 0.96 L/month for JFB, and 4.66 L/month for LFB. • 2039 Baijiu selected from China were analyzed for EC exposure and risk assessment. • EC had a high incidence (73.6%) in Chinese Baijiu. • Drinks who preferred SFB had higher EC intake. • Geographical differences influence EC formation. • MOEs showed the EC in SFB and JFB can cause cancer risk for drinkers. [ABSTRACT FROM AUTHOR]

Abstract: A survey of ethyl carbamate (EC) in fermented foods and beverages was conducted in Zhejiang province, China. The samples comprised 184 alcoholic beverages (rice wine, white spirit, wine, beer, and rice cooking wine), 33 flavorings (soy sauces and vinegars) and 20 fermented sufus. Rice wine contained up to 515μg/kg with an average of 160μg/kg, and rice cooking wine up to 206μg/kg with an average of 87μg/kg. White spirits, wine and beer contained EC at an average level of 72μg/kg, 16μg/kg and 2μg/kg, respectively. EC was also detected in soy sauces and vinegars at an average level of 47μg/kg and 27μg/kg. In fermented sufus, EC was found at an average level of 63μg/kg in normal sufu and 182μg/kg in red sufu. [Copyright &y& Elsevier]

While extracting gold and silver from telluride-type gold deposits, it is beneficial to develop a comprehensive recovery technology for tellurium. In this paper, we report process mineralogy based on the backward processing technology and the low comprehensive utilization rate of typical telluride-type gold deposits in Xiaoqinling, China. The findings show that tellurium, gold, and silver are the most valuable elements in the ore fissures and gangue minerals and are encapsulated in metallic sulfur ore in the form of altaite, hessite, calaverite, antamokite and natural gold. The flotation method was innovatively applied in this study to comprehensively recover Te, Au and Ag. The results show that when the ore particle size was −0.074 mm (70%), the flotation pulp density was 33%, the pulp pH was 8, and the combined collector (isoamyl xanthate + ethyl thio- carbamate (1:1)) was 120 g/t, in the process involving one rough flotation step, two cleaning flotations and two scavenging flotations as well as a continuous 8 d industrial test, the recovery degree was stable and the average grades of Te, Au, and Ag were 241.61, 90.30, and 92.74 g/t with 95.42%, 97.28%, and 94.65% recovery rates, respectively; thus, excellent recovery degrees were obtained. Compared with the original flotation process, the recovery rates of Te, Au, and Ag were increased by 19.91%, 6.93%, and 5.67%, which boosted the effective enrichment of all valuable elements in the telluride-type gold mine and achieved technological progress. [ABSTRACT FROM AUTHOR]