DETECTION AND QUANTITATION OF TRACE ETHYL CARBAMATE IN ALCOLLOLIC BEVERAGES BY GC/GC AND GC/GC/MS

Analytical difficulties encountered in the determination of ethyl carbamate, a known cancinogen, in a wide variety of wines and spirits have been overcome by spe- cific, sensitive GC/GC and CC/CC/MS methods with a relatively shorter extraction procedure. The lowest detection limits were estimated to be 0. 1 and 0. 01μg/L for GC/GC and GC/GC/MS respectively. The RSD of the GC/GC method was 2. 5%.

Composition of Cachacas Produced from Five Varieties of Sugarcane and the Correlation of the Presence of Dhurrin in the Cane with That of Ethyl Carbamate in the Product

The present work sought to characterize the cyanogenic glycoside dhurrin in five sugarcane varieties and to determine its possible relationship with the formation of ethyl carbamate in cachaca. For each variety, methanol, ethyl acetate and hexane extracts were prepared and submitted to thin layer chromatography. Chromatographic spots were revealed with iodine vapors. The physical and chemical parameters of the spirits produced from the five different varieties of sugar cane and by different production processes were within the legal limits. Although not exceeding the limit for ethyl carbamate, a significant variation in the final concentration of this compound was observed for each sample analyzed. The Rf values for the dhurrin standard and for the sugarcane variety SP 83-2847 were equal, similar to those for SP 80-3280 and CTC 11 and different from the Rf values for the RB 86-7515 and IAC 86-2480 samples.

Phenolic profile of jujube fruit subjected to gut microbiota fermentation and its antioxidant potential against ethyl carbamateinduced oxidative damage

Objective:To evaluate the composition of bioactive substances and the antioxidant effects of jujube fruit under gut microbiota fermentation(GMF),and the inhibitory effect on cytotoxicity caused by ethyl carbamate(EC).Methods:Changes in the contents of flavonoids,polyphenols,total sugars,and reducing sugars of jujube fruit after GMF(0,2,6,12,24,and 48 h)were determined.The oxidation resistance of fermented jujube fruits(from 0 to 48 h fermentation)was evaluated using in vitro 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate)(ABTS)and ferric reducing antioxidant power(FRAP)assays.Inhibitory effects of 48 h-fermented jujube fruit at various concentrations(0.25,0.50,1.00,and 2.00 mg/mL)on EC-treated toxicity and DNA damage of Caco-2 cells were estimated using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide(MTT)and nuclear staining assays,respectively.Effects of different concentrations of jujube fruit on EC-treated Caco-2 cells’intracellular reactive oxygen species(ROS),glutathione(GSH)levels,and mitochondrial membrane potential(MMP)were also evaluated.Results:Jujube fruit has rich bioactive components after GMF and shows strong antioxidant capacity.Fermented jujube fruit can inhibit the cytotoxicity and DNA damage of Caco-2 cells caused by EC and reduce intracellular ROS generation,as well as restoring GSH and MMP.Conclusions:Fermented jujube fruit extracts produced by GMF still contain biologically active substances which retain biological activity and antioxidation capabilities.

Polysaccharide isolated from wax apple suppresses ethyl carbamate-induced oxidative damage in human hepatocytes

Wax apple(Syzygium samarangense)has received growing research interest for its high nutritional and medicinal value due to its constituents such as polysaccharide,organic acids,flavonoids,minerals,and other substances.In this study,wax apple polysaccharide(WAP)was isolated from this plant and its protective effect against ethyl carbamate(EC)-induced oxidative damage was evaluated in human hepatocytes(L02 cells).Firstly,a series of analyses such as high-performance liquid chromatography(HPLC),high-performance gel permeation chromatography(HPGPC),Fourier transform infrared spectroscopy(FT-IR),gas chromatography/mass spectrometry(GC/MS),and 1H and 13C nuclear magnetic resonance(NMR)were conducted to identify the structure of,in vitro cell experiments were performed to verify the protective effects of WAP against EC-induced cytotoxicity,genotoxicity,and oxidative damage in L02 cells.Our results revealed that WAP is composed of mannose,rhamnose,glucuronic acid,galacturonic acid,glucose,galactose,arabinose,and fucose in a molar ratio of 2.20:3.94:4.45:8.56:8.86:30.82:39.78:1.48.Using a combination of methylation and NMR spectroscopic analysis,the primary structure of WAP was identified as Araf-(1→,Glcp-(1→,→2)-Araf-(1→,→3)-Galp-(1→,→3)-Araf-(1→,and→6)-Galp-(1→.Cell experiments indicated that WAP exhibited significant protective effects on EC-treated L02 cells via suppressing cytotoxicity and genotoxicity,reducing reactive oxygen species(ROS)and O2?-formation,as well as improving mitochondrial membrane potential(MMP)and glutathione(GSH).In a nutshell,WAP has the potential as an important therapeutic agent or supplement for hepatic oxidative damage.Meanwhile,further studies are needed to prove the above effects in vivo at the biological and clinical levels.

Elimination of ethyl carbamate in fermented foods

Ethyl carbamate (EC) is a common harmful by-product in fermented foods and can be derived from raw materials or formed during the fermentation or even in the post-treatment.Its content can be affected by temperature,microorganisms,technological processes,and other factors.In this review,we summarized the technologies and their applications for EC elimination in fermented foods in the light of upstream processes,such as raw material pretreatment,lower temperature,breeding microorganisms,and exogenous substances,to the downstream enzymatic method and physical adsorption.The review covers different strategies to eliminate EC,such as strain breeding,genetic engineering,enzyme,and physicochemical strategies.By comparing these strategies,practical strategies for the efficient elimination of EC in different fermented foods on an industrial scale have been discussed and proposed in consideration of flavor,food safety and feasibility of an industrial application.

A catalyst-free novel synthesis of diethyl carbonate from ethyl carbamate in supercritical ethanol

Diethyl carbonate has been synthesized via the alcoholysis of ethyl carbamate in supercritical ethanol under catalyst-free conditions.The influences of various parameters such as reaction temperature,reaction time,reaction pressure,ethanol/ethyl molar ratios and reaction loading volume on the yield of DEC were studied systematically.The experimental results indicated that the alcoholysis of ethyl carbamate was greatly improved in supercritical ethanol.The optimal reaction conditions were as follows：a reaction temperature of 573 K,a reaction time of 30 min,a reaction pressure of 13.2 MPa,an ethanol/ethyl carbamate molar ratio of 10 and a reactor loading volume of 285 μL respectively.The optimal yield of DEC was 22.9%.

Spectrophotometric Determination of Arginine in Grape Juice Using 8-Hydroquinoline

Arginine in grape juice can be metabolized by wine yeasts and malolactic bacteria to precursors of ethyl carbamate, known as carcinogen. The aim of this study was to develop a simple, fast, and accurate method for determining arginine in grape juice with Sakaguchi reaction by separating arginine with strong cation-exchange resins. Parameters were optimized including the concentrations of 8-hydroquinoline and sodium hydrobromite. The color stability lasted for 4 min, which is sufficient to finish the measurement. The method is simple, reproducible and accurate, and can be applied for quick measurement of arginine in grape juice to take necessary measures for controlling the level of ethyl carbamate.