MOLECULES
·
2019
·Vol. 24
·期 8
·1474
·
IF 3.06
Kai Zhou,Lorenzo Siroli,Francesca Patrignani,Yuanming Sun,Rosalba Lanciotti,Zhenlin Xu
The aim of this work was to clarify the formation of ethyl carbamate (EC) and its influence factors throughout the production process of Cantonese soy sauce. The results showed that EC was not detected in thekoji-making and earlymoromifermentation stages, but started to be generated when pH of themoromidecreased to about 4.9—at the same time, the levels of ethanol, urea and citrulline increased significantly. Most EC was formed during raw soy sauce hot extraction (40.6%) and sterilization (42.9%) stages. The EC content exhibited the highest correlation with ethanol throughout the whole production process (R = 0.97). The simulation soy sauce produced in laboratory led the same conclusion—moreover, the contents of EC, ethanol and citrulline were higher in soy sauce fermented at 30 °C than in soy sauce fermented at 15 °C. Extraction of raw soy sauce by squeezing contributed little to EC formation. Further research showed that citrulline and ethanol led to significant increases in EC levels in raw soy sauce upon heating. These results indicate that ethanol and citrulline are two critical precursors of EC and that EC is mainly formed during the heat treatment stage of soy sauce.Keywords:ethyl carbamate;soy sauce;precursor;ethanol;accumulation stage
研究领域:
食品科学
·
生物化学
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产品关联
DOI
PubMed
高影响因子
Food Analytical Methods
·
2017
·Vol. 10
·期 12
·3856-3865
·
IF 2.038
Zhou Kai,Liu Yao,Li Wen-Qian,Liu Gong-Liang,Wei Na,Sun Yuan-Ming,Bai Wei-Dong,Xu Zhen-Lin
A high-performance liquid chromatography with fluorescence detection (HPLC-FLD) method for ethyl carbamate (EC) determination in Chinese soy sauce was developed and used to predict EC precursors, and extraction, derivatization, and chromatographic conditions were optimized systematically. Under optimal conditions, the limit of detection, linear range, and recoveries were 3.91 μg/L, 12.87–274.87 μg/L, and 81.5–95.4%, respectively. The method precision was less than 8.9% (RSD) and no significant difference was found between EC determinations measured by HPLC-FLD and GC/MS. Using the proposed HPLC-FLD method, the EC contents in Chinese soy sauces ranged from not detected to 64.88 μg/L ( n = 19). Except for one soy sauce brand, the EC contents in low-salt solid-state fermented (LSF) soy sauces were lower than those in high-salt liquid fermented (HLF) soy sauces and were mainly affected by alcohol content. Moreover, the free ornithine and total arginine contents were significantly correlated with EC content in the soy sauce products. The results of this work provide a foundation for further study of EC formation and inhibition in Chinese soy sauces.
研究领域:
食品科学
·
分析化学
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产品关联
DOI
高影响因子
JOURNAL OF BIOSCIENCE AND BIOENGINEERING
·
2018
·
IF 2.015
Liu Yang,Xiaofeng Liu,Nandi Zhou,Yaping Tian
Bifunctional acid urease can not only remove urea from rice wine, but also effectively remove ethyl carbamate (EC), thereby reducing harmful substances in rice wine. Acid urease from Providencia rettgeri JN-B815 was expressed in Escherichia coli BL21(DE3) as an inclusion body . Subsequently, acid urease was refolded gradually using dilution-ultrafiltration and specific activity of 12.3 U mg −1 was obtained. The acid urease thus obtained was immobilized on graphene oxide/chitosan beads. The recovery of immobilized urease was 77% for the graphene oxide/chitosan composite when coupled for 8 h with 5% glutaraldehyde. Steady-state kinetic analysis showed that the optimum temperature for urease activity was 37°C. Time-dependent thermal inactivation studies showed that the stability of the immobilized urease improved at 37°C and the t 1/2 (half-life) of decay in urease activity was 12 h, whereas it was 43 days for soluble and chitosan/graphene oxide immobilized urease at 4°C. A significant change in K m occurred during the immobilization; the Km for urea and EC in the free state were 9.14 mM and 386 mM, respectively, whereas they were 5.28 mM and 180 mM, respectively, in the immobilized state. The values of V max for immobilized EC and urea were 1.08 μmol min −1 and 1.16 μmol min −1 , respectively, whereas they were 0.782 μmol min −1 and 0.931 μmol min −1 , respectively, for soluble EC and urea. Furthermore, 90% of the original activity of graphene oxide/chitosan–urease beads were retained after the beads were used 10 times, indicating excellent reusability.
研究领域:
生物化学
·
食品科学
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DOI
PubMed
高影响因子
Royal Society Open Science
·
2018
·Vol. 5
·期 12
·
IF 2.504
Haiyan Qi,Huacai Chen,Yan Wang,Li Jiang
Ethyl carbamate (EC), a potential carcinogen, can be formed during the fermentation and storage of alcoholic beverages. In this work, quantitative detection of EC in alcoholic beverages by using surface-enhanced Raman spectroscopy (SERS) is reported. Flower-shaped silver nanostructure substrates and silver nanocube substrates were prepared and employed as SERS platform. Flower-like silver substrates had better Raman enhancement effect on EC and were selected for further EC detection. In EC SERS spectra based on flower-shaped silver substrates, the strongest and reproducible characteristic band at 857 cm−1 was chosen for establishing a linear regression model in the concentrations ranging from 10−5 to 10−9 M, which effectively extended the application scope of the quantitative model for determination EC. Furthermore, a real alcoholic beverage was tested to verify the feasibility and reliability of the method.
研究领域:
分析化学
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食品安全
·
光谱学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 111
·109442-109452
·
IF 3.289
Zhengzong Wu,Enbo Xu,Jingpeng Li,Jie Long,Aiquan Jiao,Zhengyu Jin
A simple and reliable method for fast extraction and sensitive detection of ethyl carbamate (EC) in rice wine and fruit brandy based on the integration of molecularly imprinted polymers and surface-enhanced Raman spectroscopy (MIPs–SERS) was developed. Molecularly imprinted polymer microspheres were synthesized as artificial antibodies towards EC. Adsorption tests and thermogravimetric analysis validated the specific selectivity and stability of MIPs respectively. The synthesized MIPs was used as sorbents in solid-phase extraction (SPE) and could selectively separate and enrich EC from rice wine and fruit brandy samples with little interference. A silver dendrite nanostructure was employed as a SERS-active substrate for the enhancement of Raman signals. Spectra processed by principal component analysis (PCA) can clearly differentiate Raman signatures of wine samples with various EC contents. A partial least square (PLS) regression model demonstrated a good fitting effect (the correlation coefficient of calibration and prediction were 0.9614 and 0.9456, and 0.9559 and 0.9393 respectively for rice wine and fruit brandy) between the predicted and the reference data of EC in rice wine and fruit brandy samples. Our results show that the high selectivity of MIPs and the fingerprint Raman identification can be integrated into a novel nano-biosensor for fast and efficient detection of hazardous substances (EC) in complex rice wine and fruit brandy samples.
研究领域:
分析化学
·
食品安全
·
纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）