• Korean Journal of Food Science and Technology
• /
• v.39 no.1
• /
• pp.94-98
• /
• 2007

Ethyl carbamate, which is also known as a possible human carcinogen, is formed by ethanolysis of N-carbamyl compounds such as carbamyl phosphate, urea, or citrulline. NaCl that is highly present in fermented foods was suspected to have an influence on ethyl carbamate formation. This study was designed to determine the effect of NaCl on the chemical reactions upon incubation of ethanol with the N-carbamyl compound in a 25% NaCl solution or in the absence of NaCl, and to find a possible association with the formation of ethyl carbamate. While the amount of ethyl carbamate formed in a urea solution with the addition of NaCl was increased up to 26%, the amount formed with citrulline or carbamyl phosphate in the presence of NaCl was decreased up to 30% and 40%, respectively. This indicates that NaCl should be considered as a potential factor influencing the rate of ethyl carbamate formation from its precursors.

• Korean journal of food and cookery science
• /
• v.13 no.2
• /
• pp.92-98
• /
• 1997

Ethyl carbamate is an animal carcinogen and a by-product of fermentation. Since the highest level of ethyl carbamate was found in a traditional soy sauce sample in the previous study, soysauce was prepared in varying experimental conditions with three kinds of meju originated from different area of the country to investigate the factors affecting ethyl carbamate formation. The sample analysis methods included a semi-purification with solid-phase extraction and detection by GC-MS at SIM mode using m/z 62 fragment ion. Among the investigated factors, which includes source meju, bringing length, salt content, irradiation of visible light during bringing or storage, and storage length, source meju and storage length showed most profound effect on the formation of ethyl carbamate. Irradiation of visible light for 12 hours a day during storage lowered the concentration of ethyl carbamate compared to the soysauce kept in the dark. Meanwhile irradiation during the bringing as well as the degree of salt contents showed no effect.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.12
• /
• pp.1410-1412
• /
• 2001

• Journal of the East Asian Society of Dietary Life
• /
• v.7 no.1
• /
• pp.41-46
• /
• 1997

Diet is generally accepted as one of the important factors in human cancer development. Ethyl carbamate has been associated with cancer for several decades and mainly found in the fermented beverages and foodstuff. The relationship between ethyl carbamate and the human health cannot be ignored especially in the areas where fermented foods consists of regular food consumption. To investigate the ethyl carbamate exposure level in Korean population, commercial fermented food samples were collected form local markets I Seoul area and home-made varieties were collected throughout the country. Following partial purification the concentration of ethyl carbamete was determined by GC/ MS. The concentration of ethyl carbamate ranged to 70 ppb in soysauce, to 10 ppb in soybean paste, and to 5 ppb in vinegars. Korean traditional alcoholic beverages showed small amount of ethyl carbamate. The estimated daily exposure of Korean population was 0~1900ng/day. It would be prudent to put efforts to minimize the formation of ethyl carbamate since the risk from the higher range exposure cannot be ignored.

• Toxicological Research
• /
• v.16 no.1
• /
• pp.9-16
• /
• 2000

Ginseng (the root of Panax ginseng C. A. Meyer, Araliaceae) has been used for traditional medicine in China, Korea, Japan and other Asian countries. It is most often used as a general tonic, and it involves a wide range of pharmacological actions, such as antiaging, adaptogen-like effect to foreign deleterious infringement, immunoenhancement, antistress, antitumor, and antioxidant actions. Red ginseng showed anticarcinogenic activity against various chemical carcinogens in mouse and cancer-preventive effect of human being as on mice in experimental and epidemiological studies. In the present study, we have found the protective properties of red ginseng against vinyl carbamate (VC) which is the proximate carcinogen of ethyl carbamate and its ultimate carcinogenic epoxides. Red ginseng exhibited dose-dependent inhibition on the mutagenci activities of boty VC in the presence of S9 mix and vinyl carbamate epoxide (VCO) without metabolic activation in Salmonella typhimurium TA1535. Formation of DNA adducts from VCO was also attenuated in the presence of red ginseng. Oral administration of red ginseng prior to the topical application of each of the above carcinogens and TPA treatment resulted in significant reduction in both incidence and multiplicity of skin tumors in mice. These results indicate that red ginseng possesses a strong chemopreventive effect against mouse skin carcinogenesis induced by VC or VCO.

• Korean Journal of Food Science and Technology
• /
• v.28 no.3
• /
• pp.421-427
• /
• 1996

Ethyl carbamate is an animal carcinogen and a suspected human carcinogen found in fermented foods and beverages. For the determination of ethyl carbamate in typical Korean diet, an analytical method was established for the food as complex as Kimchi. Kimchi samples collected from various locations in the country were homogenized and extracted four times with ethyl acelate. Following concentration and reconstitution with water, the extract was loaded onto $C_{18}$ column. Fraction containing ethyl carbamate was eluted with methanol, while most of the red pigment of the sample was retained on the column. The eluent was further purified with alumina, followed by Florisil column. The final eluent was analyzed by gas chromatography mass spectrometry in the selected ion monitoring mode. None of the twenty Kimchi samples showed ethyl carbamate level higher than 4.6 ppb without correction for the recovery. The concentration of ethyl carbamate in Kimchi increased as pH decreased, suggesting fermentation dependent formation of ethyl carbamate.

• Journal of Food Hygiene and Safety
• /
• v.24 no.3
• /
• pp.194-199
• /
• 2009

The effects of part of plum, alcohol content and addition of t-resveratrol on the formation of ethyl carbamate during the fermentation for wine were investigated at a time interval (45 days) for 6 months. The concentration of the ethyl carbamate in plum wine was determined according to KFDA guideline for ethyl carbamate analysis. In the plum wine with 16% or 30% alcohol content, the concentrations of ethyl carbamate were increased with time of fermentation periods. The maximum concentrations of ethyl carbamate in 16% and 30% plum wines after the fermentation for 6 months were $0.071{\mu}g$/g and $0.188{\mu}g$/g, respectively. When t-resveratrol was added at the level of $10{\mu}g$/g in both 16% and 30% plum wine, the concentrations of ethyl carbamate at 6 months were 0.078 and $0.216{\mu}g$/g, respectively. The addition of t-resveratrol at the level of $300{\mu}g$/g in both 16% or 30% plum wine, the concentrations of ethyl carbamate at 6 months were 0.078 and $0.169{\mu}g$/g, respectively. The ethyl carbamate in the plum wine was not formed during fermentation for 6 month as using the flesh of plum, but $0.588{\mu}g$/g of ethyl carbamate was formed as using plum with plum seed. The addition of $300{\mu}g$/g of t-resveratrol actually increased the concentration of the ethyl carbamate by $0.088{\mu}g$/g as fermented for 6 months using plum with seed. These results suggest that the flesh of plum should be used to reduce the formation of ethylcarbamate for production of plum wine and that the addition of t-resveratrol during fermentation of plum wine can not reduce the concentration of the ethyl carbamate.

• Environmental Mutagens and Carcinogens
• /
• v.17 no.2
• /
• pp.97-108
• /
• 1997

The drugs or xenobiotics introduced to the body, are detoxified through the process of biotransformation in the body. In this process, most of the insoluble compounds become more polar, soluble and easily excretable. But, parts of introduced materials are metabolized to highly reactive electrophilic carcinogens through activation pathways. These metabolites are toxic and can react with DNA, RNA and proteins which are nucleophilic compounds. The objective of this study is to illustrate the aleactivation pathways of two highly reactive epoxide compounds, vinyl carbamate epoxide (VCO) and 2'-(4-nitrophenoxy)oxirane (NPO). They are the ultimate electrophilic carcinogens of ethyl carbamate(urethane) and 4-nitrophenyl vinyl ether, respectively. In this research, we studied the inhibition of the mutagenic activities of VCO or NPO by nuchieophiles [glutahione(GSH) and N-acetylcysteine(NAC)], detoxifying enzymes[epoxide hydrolase and glutathione-S-transferase(GST)] and intracellular organelles (microsomes and cytosol). In addition we also tested the suppression of DNA adducts formation by GSH and NAC. The results are summerized as follow. 1. The microsomes and cytosol which contain epoxide hydrolase and GST, respectively, decreased the mutagenicity of VCO (74% and 95%, respecfivel), and NPO (35% and 93%, respectively). The nucleophilic GSH and NAC decreased the mutagenicity by 86% (VCO) and 80% (NPO), 76% (VCO) and 40% (NPO), respectively. 2. The purified epoxide hydrolase decreased the mutagenicity of two epoxides in a dose-dependent manner, and GSH also decreased the mutagenicity in the presence of GST. 3. Formation of two DNA adducts, 7-(2'-oxoethyi)guanine (OEG) and N2,3-ethenoguanine(EG), were compared in the presence of calf thymus DNA and epoxide (VCO or NPO) in vitro system. The amounts of DNA adducts were decreased in the presence of GSH (25% and 29% in VCO, 32% and 29% in NPO), and NAC (14% and 16% in VCO, 21% and 11% in NPO), respectively. From these results, it is concluded that the ultimate carcinogenic metabolites, VCO and NPO, can be made in the body, but much of them may be inactivated and detoxified by the nucleophilic GSH, NAC and detoxifying enzymes (epoxide hydrolase and GST). Therefore, by these mechanism, the formation of DNA adducts and mutagenic activities of these two epoxides may be lowered in vivo.

• Korean journal of food and cookery science
• /
• v.31 no.2
• /
• pp.112-117
• /
• 2015

The analytical method for ethyl carbamate (EC) in maesil (Prunus mume) extract was developed with deuterium-labeled ethyl carbamate as an internal standard. Samples were neutralized with an addition of 1 N sodium hydroxide solution, followed by a solid phase extraction with a Chem Elut cartridge. A standard curve exhibited a good linearity with correlation coefficient of 0.9991. The limit of detection (LOD) and limit of quantification (LOQ) were 2.91 ng/g and 8.83 ng/g, respectively. The recovery rate of EC ranged from 91.40% to 120.90%. The precision never exceeded 12.57% (intra-day) and 11.03% (inter-day). Samples were comprised of 24 home-made and 7 commercially-available maesil extracts. Eight home-made samples contained EC at levels between 3.39 and 75.76 ng/g. Three commercially-available samples had EC at levels between 11.67 and 20.16 ng/g. Average daily intakes of EC from maesil extracts for consumers were 0.23 g/kg of body weight. Based on a benchmark dose confidence limit ($BMDL_{10}$) of 0.25 mg/kg of body weight/day, the margin of exposure (MOE) of EC in maesil extract for consumers was 94,150, which is not of concern. Considering that a daily intake of maesil extract has been increasing, further studies on the formation of EC in maesil extract is needed.

• Food Science and Preservation
• /
• v.20 no.3
• /
• pp.429-434
• /
• 2013

This study was designed to investigate the formation of ethyl carbamate (EC) during the ripening of Maesil with sugar and Soju (19.5~35% alcohol contents) using a homemade method. Maesil, sugar and Soju were purchased at ordinary market in June of 2012. The preparation of sample for analysis was conducted by method of Henry et al. The analysis of GC/MS was used SIM mode (m/z 89, 74, 62). Quantification was performed in terms of the 62 ion and was based on an internal standard procedure. Good linearity was obtained with a regression coefficient ($r^2$ = 0.993). Low detection limits (LOD) was achieved 4.31 ug/kg and recovery for alcohol was 74.8%. During 90 days, fermentation with sugar was not detected EC (under LOQ). 15 days ripened Maesil wine contained EC between non detected~32.7 ug/kg and 90 days ripened Maesil wine was 19.7~87.4 ug/kg. Higher proportion of Maesil and Soju increased EC contents. EC levels were increased 32.7 ug/kg to 87.4 ug/kg in the ratio of Maesil to 35% alcohol-Soju (1:1). In the ratio of Maesil to 35% alcohol-Soju (1:3) was increased non detected to 69.7 ug/kg. After 90 days, Maesil wine was filtered Maesil through a seive and ripened by 180 days to investigate the formation of EC compared with non filtered. Treatment of filtered, EC contents was much higher level compared with non filtered. Therefore, this result showed that alcohol contents contribute to increase EC formation more than Maesil.