食品过敏原大豆成分LAMP实时浊度检测法的建立

根据过敏原大豆的保守内源基因Lectin的序列,设计6条特异性LAMP引物,利用实时浊度仪对反应体系中扩增产物的实时监控筛选出最佳引物,建立食品中过敏原大豆成分的环介导等温扩增(LAMP)检测方法,并对该方法的特异性、灵敏度、稳定性进行了评价。结果表明:该方法能够特异性检出食品中的过敏原大豆成分,特异性高,灵敏度达0.1%(w/w)。对含有大豆成分为10%、1%、0.1%、0%(w/w)的样品分别进行20次重复实验,其稳定性好,假阳性和假阴性率为0%。本实验建立的LAMP方法适用于特异性快速检测食品中的过敏原大豆成分。     

食品过敏原羽扇豆成分的环介导等温扩增 检测方法

目的 建立食品过敏原羽扇豆成分的环介导等温扩增(LAMP)检测方法。方法 根据羽扇豆的ITS基因设计羽扇豆的特异性引物,进行特异性、灵敏度、稳定性测试,建立LAMP检测方法。结果 本文建立的食品过敏原羽扇豆成分LAMP检测方法能有效对羽扇豆成分进行快速检测,具有较强的特异性和稳定性,灵敏度可达0.001%(w/w)羽扇豆粉。结论 该方法特异性强,灵敏度高,可以快速、准确检测食品中过敏原羽扇豆成分。     

食品过敏原羽扇豆成分的环介导等温扩增检测方法

目的建立食品过敏原羽扇豆成分的环介导等温扩增检测方法(loop-mediated isothermal amplification,LAMP)。方法根据羽扇豆的ITS基因设计羽扇豆的特异性引物,进行特异度、灵敏度、稳定性测试,建立LAMP检测方法。结果本文建立的食品过敏原羽扇豆成分LAMP检测方法能有效对羽扇豆成分进行快速检测,具有较强的特异度和稳定性,灵敏度可达0.001%(w:w)。结论该方法特异度强、灵敏度高,可以快速、准确检测食品中过敏原羽扇豆成分。     

环介导等温扩增技术快速检测植物蛋白饮料中大豆成分

目的 建立植物蛋白饮料中大豆成分环介导等温扩增（Loop-mediated isothermal amplificantion,LAMP）快速检测技术方法。方法 根据大豆Lectin基因保守序列,设计大豆成分环介导等温扩增检测特异性引物和反应体系,对方法特异性、灵敏度和稳定性进行测试,并以实时荧光PCR方法为参比方法,对32种植物蛋白饮料进行检测应用验证。结果 本研究建立的LAMP方法特异性强,稳定性好,最低检出限为0.1%（以质量分数计）;通过参比方法验证,方法特异性和灵敏度为100%,不存在假阳性和假阴性。结论 本研究建立的LAMP技术快速检测植物蛋白饮料大豆成分的方法具有操作简单、快速准确、检测成本低等优点,可为植物蛋白饮料大豆成分掺杂掺假提供一种快速检测方法。     

环介导等温扩增技术快速检测食品过敏原牡蛎成分

目的建立环介导等温扩增(loop-mediated isothermal amplification, LAMP)方法快速检测食品中的过敏原牡蛎成分。方法根据国家生物技术信息中心的牡蛎线粒体序列,通过Primer Explorer version 5.0软件设计引物并筛选出LAMP特异性扩增引物。并进一步对反应体系优化,对该方法的灵敏度、特异性以及稳定性进行验证。对10种牡蛎阳性样品、14种阴性样品、4类牡蛎相关食品进行检测。结果该方法可以检测出含牡蛎成分0.1%, DNA浓度为0.01 ng/μL的样品。在实验时间上大幅缩短,反应可在25～45 min内结束,并且可以在微量体系下完成,对于食品相关产品的检出率为100%。结论该方法操作简单、成本较低、特异性高、灵敏度好,适用于食品中过敏原牡蛎成分的检测。     

环介导等温扩增技术在食品安全检测领域的应用研究进展

环介导等温扩增技术(Loop-mediated isothermal amplification,LAMP)是近年发展起来的一种新型核酸检测技术。其采用特异识别靶序列上6个位点的4条引物和一种具有链置换活性的DNA聚合酶,在等温条件下进行核酸扩增,与传统核酸检测技术(PCR法、实时荧光定量PCR法)相比,具有操作简单、特异性强、灵敏度高、可肉眼判读结果等优点。核酸检测是食品安全检测技术的一个重要手段,本文综述了LAMP技术在食品微生物检测、转基因成分检测、过敏原成分检测和动物源性成分检测领域的应用研究进展,探讨了LAMP技术在食品检测领域的发展前景,以期为食品快速、高通量检测技术建立提供参考。     

小麦成分环介导等温扩增现场快速检测方法的建立和应用

目的建立环介导等温扩增(loop-mediated isothermal amplification,LAMP)方法现场快速检测小麦过敏原成分的分析方法,有助于食品安全突发事件现场和食品企业生产过程中的样品检测小麦成分。方法运用LAMP建立食品过敏原小麦成分LAMP现场快速检测方法,采用实时浊度仪和显色法进行结果判断,并进行反应条件优化。结果本方法特异性强,对35个对照样品无交叉反应;方法的灵敏度高,检测限可达到0.01%小麦;方法稳定性好,对0.1%和0.01%小麦样品重复检测结果稳定。通过对市场采集70份样品检测结果显示,该方法与食品标签标示的过敏原成分结果一致。结论本方法操作简单,检测时限短,结果判断准确,可用于过敏原小麦成分的快速检测。     

食品中芥末过敏原成分LAMP检测方法的建立

目的：建立食品过敏原芥末成分环介导等温扩增（loop-mediated isothermal amplification,LAMP）检测方法,并与实时荧光-聚合酶链式反应（real-time polymerase chain reaction,RT-PCR）检测方法比对。方法：针对白芥的主要过敏原基因Sin A1,设计LAMP引物并建立反应体系,在特异性和灵敏度方面与RT-PCR检测方法比对。结果：建立的LAMP检测方法,经特异性验证,与所测试的13 种植物,无交叉反应。通过添加实验,方法的检测灵敏度为0.5%,与RT-PCR方法检测灵敏度相当。检测了25 份实际样品,检测结果与RT-PCR检测结果一致。结论：建立的食品过敏原芥末成分LAMP检测方法简单经济,检测结果可靠,可有效缩短检测时间,适用于芥末过敏原成分
的检测,具有良好的应用前景。     

环介导等温扩增技术快速检测变形杆菌属的研究

建立了一种快速、灵敏、高度特异的检测变形杆菌属(Proteus)的方法——环介导等温扩增技术(loop-mediated isothermal amplification,LAMP)。通过对GenBank中变形杆菌属atpD基因序列(AX109601)进行分析,设计了6条引物(2条内引物、2条外引物、2条环引物),在Bst大片段聚合酶的作用下,对模板DNA进行梯状等温扩增,产生白色沉淀,并且优化LAMP的反应体系,检验其灵敏性与特异性。扩增产物用限制性内切酶Psp1406Ⅰ(AclⅠ)酶切,观察酶切片段大小,验证方法的正确性。结果表明,该方法在61℃保温50 min即可完成,最低检测限为5.4 CFU/mL,灵敏度高于常规PCR 10倍。对其它食品病原菌进行检测,结果均未出现目的条带。表明LAMP法检测变形杆菌属灵敏度高、特异性好,操作简便,无需特殊的仪器设备,有恒温加热设备就可以满足检测条件,极适合在我国广大基层实验室开展应用。     

环介导等温扩增技术检测食品中铜绿假单胞菌

建立食品中铜绿假单胞菌环介导等温扩增(LAMP)检测方法。利用铜绿假单胞菌外毒素A(PEA)基因序列,设计3对铜绿假单胞菌LAMP检测特异性引物,用36株铜绿假单胞菌,14株近源菌验证方法的特异性。建立的LAMP方法特异性好,灵敏度达到2.2 cfu/100 g~3.5 cfu/100 g。建立的食品中铜绿假单胞菌LAMP检测方法特异性好,灵敏度高,适用于的检测食品中的铜绿假单胞菌。     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.