基于RPA-LFD法的多黏菌素耐药基因mcr-1可视化快速检测方法建立与应用

目的：建立一种快速、高效、可视化的细菌多黏菌素耐药基因mcr-1检测方法，为其基层检测的展开提供依据和便利。方法：利用重组酶聚合酶扩增结合胶体金侧向流试纸条技术(Recombinase polymerase amplification combined with a lateral flow dipstick,RPA-LFD)，辅以手持式胶体金读数仪；根据mcr-1基因保守序列设计合成一对特异性RPA引物，通过对反应条件和体系的优化，以及特异性试验、灵敏度试验、模拟食样试验和实际样品试验，成功建立了可视化定量检测细菌多黏菌素耐药基因mcr-1的RPA-LFD方法。结果：在引物浓度400 nmol/L，引物比例1:1时，该方法最佳反应条件为Mg²⁺浓度14.0 mmol/L，反应温度37℃，反应时间20 min；灵敏度好，标准曲线方程为y=0.117x+0.051，定量限为10¹～10⁸ copies/μL，检出限为10¹ copies/μL，比PCR法低一个数量级且模拟样品检出结果与PCR法一致。利...     

基于检测概率模型的表面增强拉曼光谱法快速筛查果蔬中多菌灵残留

目的 建立一种水果蔬菜中多菌灵残留的表面增强拉曼光谱(SERS)快速筛查方法。方法 样品经乙醇提取、二氯甲烷净化、氮吹浓缩和乙醇溶液复溶四步获取待测液,通过单因素实验,优化金纳米粒子、提取液、萃取试剂及促凝剂的加入量,确定拉曼光谱仪的仪器测试条件。结果 多菌灵的拉曼特征位移为 630±5 cm^-1、728±5 cm^-1、1 002±5 cm^-1、1 224±5 cm^-1、1 264±5 cm^-1、1 316±5 cm^-1,根据其拉曼光谱特征峰及其强度,对多菌灵进行定性快速测定。结合检出概率模型(POD),确定出多菌灵在苹果、柑橘等水果中的检出限为 0. 5 mg/kg,在辣椒等蔬菜中的检出限为 1. 0 mg/kg。结论 本方法操作简单、快速准确,从样品前处理到结果显示仅需 40 min,结合使用 POD 模型,验证了该方法的有效性,可应用于水果蔬菜中多菌灵的现场快速检测。     

SERS结合手持式拉曼光谱仪快速检测保健食品中西布曲明的研究

目的：运用表面增强拉曼光谱法快速测定保健食品中非法添加的西布曲明。方法：采用表面增强试剂对保健食品进行快速处理,然后使用手持式拉曼光谱仪对其进行快速定性分析。结果：金、银溶胶两种表面增强试剂均能检测出保健食品中的西布曲明,准确判断出阳性样品和阴性样品,其中金溶胶检测效果更佳,检出限为10μg·mL^-1。结论：SERS结合手持式拉曼光谱仪可以应用于保健食品中非法添加的西布曲明的快速筛查,提高执法效率。     

基于检出概率模型的牛奶中恩诺沙星和环丙沙星总量的拉曼光谱现场快速检测的研究

目的 建立牛奶中恩诺沙星和环丙沙星总量的表面增强拉曼光谱快速检测方法。方法 前处理采用5%乙酸水溶液提取、二氯甲烷液-液分配净化。通过单因素实验,确定胶体银、提取液及促凝剂等表面增强最优参数。结果 恩诺沙星和环丙沙星增强后的拉曼光谱特征位移为(736±5)cm^-1、(785±5)cm^-1、(1 345±5)cm^-1、(1 395±5)cm^-1。根据定性方法验证的检出概率模型,确定牛奶中恩诺沙星和环丙沙星检出限为50μg/kg。结论 本方法前处理操作简单,从样品前处理到出具结果仅需25 min,可用于牛奶中的恩诺沙星和环丙沙星的现场快速检测。     

QuEChERs方法结合SERS技术检测猪肉中氨基糖苷类抗生素残留

目的:实现猪肉中氨基糖苷类抗生素残留的快速、定量和高通量检测。方法:以PP合成纸为衬底制备基于金纳米花(AuNFs)的方阵排列SERS基底。通过QuEChERs方法对猪肉样品进行前处理,并对其进行SRES检测。结果:采用4-巯基苯甲酸为SERS探针分子,基底表现出良好的均一性、SERS增强效应、重现性和稳定性。475,619 cm^-1特征峰处的SERS信号强度分别与硫酸庆大霉素和硫酸新霉素浓度的对数具有良好的线性关系(R²分别为0.991 6,0.990 7),最低检测限分别低至1×10^-9,1×10^-8 mol/L,并成功应用于猪肉中氨基糖苷类抗生素的快速、定量和高通量检测。结论:试验方法为SERS技术应用于真实肉类样品中抗生素残留检测提供了一种经济、高效、省时和高灵敏的途径。     

3种常见食源性致病菌多重重组酶聚合酶扩增检测方法研究

目的建立了食品中沙门菌、单核细胞增生李斯特菌和蜡样芽胞杆菌多重重组酶聚合酶扩增（recombinase polymerase amplification,RPA）快速检测方法。方法选择沙门菌invA基因、单增李斯特菌hlyA基因和蜡样芽孢杆菌16S RNA序列为目标基因进行扩增,建立并优化多重RPA扩增体系和扩增条件;评价反应体系的特异性和灵敏度,并对人工污染食品样品和实际样品进行检测。结果多重RPA反应体系能够在20 min完成三种目标基因的扩增,特异性强;对沙门菌、单增李斯特菌和蜡样芽孢杆菌的灵敏度分别为2.70×105、1.30×105、1.44×104 CFU/mL;能够用于人工污染样品和实际样品的检测。结论本研究建立的多重RPA等温扩增方法特异性强,操作快速、简单,为食源性致病菌的快速检测提供新方向     

多重聚合酶链式反应技术检测罗非鱼5种常见食源性致病菌

目的 建立一种可同时检测无乳链球菌(Streptococcus agalactiae)、嗜水气单胞菌(Aeromonas hydrophila)、霍乱弧菌(Vibrio cholerae)、大肠杆菌(Escherichia coli)和沙门菌(Salmonella) 5种罗非鱼常见食源性致病菌的多重聚合酶链式反应(polymerase chain reaction,PCR)方法。方法 根据5种致病菌特异性基因片段设计并合成引物,优化多重PCR体系条件,并对多重PCR体系的特异性、灵敏度以及人工模拟样品进行检测。结果 建立的多重PCR方法可同时扩增5种目的菌株的特异性条带,且不与非靶标细菌发生交叉反应。敏感性实验结果显示,该方法对无乳链球菌、嗜水气单胞菌、沙门菌、霍乱弧菌、大肠杆菌纯培养物基因组DNA的检出限均为0.4 ng/μL。人工模拟样品检测结果显示,该方法可以快速且准确地检测上述5种食源性致病菌,且检出限可达到2×10¹ CFU/g。结论 本研究建立了一种可同时检测无乳链球菌、嗜水气单胞菌、霍乱弧菌、大肠杆菌和沙门菌5种罗非鱼常见食源性致病菌的多重PCR检测...     

基于纳米银颗粒团聚反应的表面增强拉曼光谱法测定牛奶中三聚氰胺的含量

建立表面增强拉曼(surface-enhanced raman scattering,SERS)技术检测牛奶中三聚氰胺含量的方法。以金属钛板作为SERS衬底材料,采用50 nm银纳米颗粒作为基底,控制银溶胶与样品的体积比为1∶2,Na Cl和Na OH溶液的浓度为4 mol/L,通过便携式拉曼光谱仪采集样品的SERS信号。在质量浓度0. 2～10 mg/L的范围内,SERS强度随着牛奶中三聚氰胺浓度的增大而增强,线性相关系数R~2=0. 998,检测限为0. 08 mg/L。使用银纳米基底对1 mg/L加标样品平行测定20次,三聚氰胺特征峰强度的相对标准偏差为4. 34%。此法简单易行,重现性好、稳定性高,可实现对牛奶中三聚氰胺含量的快速检测,为食品中污染物的SERS检测提供了参考价值。     

利用磁固相萃取技术结合表面增强拉曼散射快速检测葡萄汁中的三唑磷

目的 建立磁固相萃取技术结合表面增强拉曼散射(surface enhanced Raman scattering, SERS)法快速检测葡萄汁中的三唑磷。方法 以Fe3O4为磁芯,三醛基间苯三酚(trihydroxy-benzene tricarbaldehyde, Tp)和联苯胺(benzidine, BD)为配体合成共价有机框架(covalent organic framework,COF)包裹的磁性纳米材料Fe3O4@COF (TpBD)。以Fe3O4@COF (TpBD)为吸附材料,通过π-π相互作用和氢键作用吸附样品溶液中的三唑磷,实现复杂基质中三唑磷的分离和富集。以金纳米颗粒为SERS增强基底,结合便携式拉曼光谱仪建立一种三唑磷的快速检测和定量分析方法。结果 利用1000、1409和1596 cm-1拉曼位移处的SERS信号强度计算的三唑磷检出限分别为2.97、3.57和3.44 nmol/L,相关系数分别为0.9647、0.9677和0.9579。利用该方法检测葡萄汁中三唑磷的回收率为67.56%~86.80%,相对标准偏差为0.99%~1.68%。结论 本研究建立的磁固相萃取结合SERS方法在三唑磷的快速检测和定量分析中表现出了良好的灵敏度、准确性和稳定性,具有应用于果汁中三唑磷快速检测的潜力。     

重组酶聚合酶扩增技术检测转基因水稻中的Cry1Ab/c基因

重组酶聚合酶扩增技术(RPA)是利用重组酶和单链结合蛋白在常温下协同实现引物与模板的特异结合,以代替传统PCR热循环中的变性和复性过程的新型恒温体外核酸扩增技术。本研究基于RPA技术建立了转基因水稻Cry1Ab/c基因的检测方法,可在37℃恒温条件下快速检测到转基因水稻中的Cry1Ab/c基因,具有较好的特异性,其绝对及相对检测灵敏度分别达到100个拷贝和0.1%(质量分数),适用于基层实验室及现场快速检测转Cry1Ab/c基因水稻及其制品。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the