赭曲霉毒素A胶体金快速检测试剂条的研制

为建立一种快速检测饲料中赭曲霉毒素A的检测方法,应用胶体金免疫层析技术,研制了一种饲料中赭曲霉毒素A的免疫胶体金快速检测试剂条.将羊抗鼠IgG、特异性结合抗原和金标抗体三者经过反复调试优化,以适宜浓度和包被量分别包被到硝酸纤维素膜和胶体金结合垫上,包被后的硝酸纤维素膜、样品垫、胶体金结合垫、吸水垫及其他辅料组装成试剂条.试剂条的最低检测限为25μg/kg,与其他霉菌毒素的交叉反应率小于1％.该试剂条可用于饲料中赭曲霉毒素A的快速检测.     

胶体金免疫层析法快速检测黄曲霉毒素B1的研究

本文应用胶体金免疫层析技术,建立了一种快速检测食品中黄曲霉毒素B1的方法。采用柠檬酸三钠还原法制备胶体金颗粒,标记抗黄曲霉毒素B1单克隆抗体并喷于玻璃纤维上,黄曲霉毒素B1偶联抗原和二抗鼠抗驴分别结合于硝酸纤维膜上,依次将样本垫、胶金垫、硝酸纤维膜和吸水纸组装切割成胶体金试纸条并装入检测卡中。测试结果表明黄曲霉毒素B1快速检测试纸条的灵敏度为5ng/ml,检测时间为10min,批内和批间重复性为100%,假阳性率和假阴性率均为0。使用简单方便,非常适合现场快速检测黄曲霉毒素B1。     

一种快速检测食用油中黄曲霉毒素B1的胶体金试剂板的研制

为建立用于快速检测粮油样品中黄曲霉毒素B1药物残留含量的胶体金免疫层析检测试剂,采用免疫竞争法,将抗黄曲霉毒素B1单克隆抗体-胶体金复合物包被在微孔中,并将人工合成的黄曲霉毒素B1抗原包被在硝酸纤维素膜(NC膜)表面作为检测线(T线).待测样品中的黄曲霉毒素B1残留物将与NC膜上的黄曲霉毒素B1抗原竞争结合胶体金标记的抗黄曲霉毒素B1单克隆抗体,并以颜色直观显示检测结果.检测食用油样品时,灵敏度可达到0.5 μg/L,仅需20 min.试验证明该检测试剂具有较高的灵敏度及很好的特异性,操作便捷,稳定可靠,可作为黄曲霉毒素B1残留现场监控的有效快速筛检手段.     

利用荧光免疫层析卡测定黄曲霉毒素M1的研究

将量子点与抗黄曲霉毒素M1(AFM1)的单克隆抗体偶联,以AFM1-BSA偶联物包被于NC膜作为检测线,山羊抗鼠二抗包被于NC膜上作为质控线,构建了直接竞争检测AFM1的荧光定量免疫层析检测卡体系,在0.156μg/L~1.25μg/L范围内能够准确定量黄曲霉毒素B1,灵敏度达到0.156μg/L。     

胶体金免疫层析法快速检测T-2毒素的研究

应用胶体金免疫层析技术,建立了一种快速检测谷物和饲料中T-2毒素的方法.采用柠檬酸三钠还原法制备胶体金颗粒,标记抗T-2毒素单克隆抗体并喷涂于玻璃纤维上,T-2毒素偶联抗原和羊抗鼠二抗分别喷涂于硝酸纤维素膜上,作为检测线和质控线,依次将样品垫、胶体金垫、硝酸纤维素膜和吸水垫组装成试纸条并装入检测卡中.测试结果表明,T-2毒素快速检测试纸条的检测限为0.Smg/L,检测时间为10min,假阳性率和假阴性率均为0.该法使用简单方便,非常适合现场快速检测谷物和饲料中的T-2毒素.     

玉米赤霉烯酮胶体金快速检测试剂板的研制

目的 应用胶体金免疫层析技术, 研制一种玉米等谷物中玉米赤霉烯酮残留免疫胶体金快速检测试剂板。方法 将制备的羊抗鼠IgG、人工结合抗原和金标抗体三者经过反复调试优化, 以适宜浓度和包被量分别包被到硝酸纤维素膜和胶体金结合垫上。包被后的硝酸纤维素膜和样品垫、胶体金结合垫、吸水垫及其他辅料组装成试纸条。结果 该试剂板的最低检测限为100 μg/kg, 整个检测过程仅15 min, 与其他霉菌毒素无交叉反应。结论 该试剂板可用于玉米赤霉烯酮残留快速检测。     

胶体金免疫层析法快速检测食用油中黄曲霉毒素残留

为建立用于快速检测粮油样品中黄曲霉毒素药物残留含量的胶体金免疫层析检测试剂,我们采用免疫竞争法,将抗黄曲霉毒素单克隆抗体-胶体金复合物包被在微孔中,并将人工合成的黄曲霉毒素抗原包被在硝酸纤维素膜(NC膜)表面作为检测线(T 线)。待测样品中的黄曲霉毒素残留物将与NC膜上的黄曲霉毒素抗原竞争结合胶体金标记的抗黄曲霉毒素单克隆抗体,并以颜色直观显示检测结果。检测食用油样品时,灵敏度可达到0.5μg/L,仅需20 min。实验证明该检测试剂具有较高的灵敏度及很好的特异性,操作便捷,稳定可靠,可作为黄曲霉毒素残留现场监控的有效快速筛检手段。     

牛奶中黄曲霉毒素M1胶体金试纸条的研究

应用胶体金免疫层析技术,建立一种快速检测牛奶中黄曲霉毒素M1的方法。采用柠檬酸三钠还原法制备胶体金颗粒,单克隆抗体胶体金标记物的制备并冻干成微孔试剂,样品吸收垫和反应膜的制备,试纸条的组装。所研制的黄曲霉毒素M1快速检测试纸条的检测限为0.3μg/L,检测时间为10 min,假阳性率和假阴性率为0。试纸条使用简单方便,适合进行现场快速检测牛奶中残留的黄曲霉毒素M1。     

胶体金免疫层析技术快速检测谷物中3种真菌毒素的研究

目的应用胶体金免疫层析技术开发一种快速检测谷物中黄曲霉毒素B1(AFB1)、玉米赤霉烯酮(ZEN)和呕吐毒素(DON)的三联检测卡。方法优化胶体金溶液p H值、金标抗体量及抗原包被量制备3种胶体金试纸条,将试纸条组装成检测卡,研究该卡的检测限、准确度、特异性和稳定性。结果 AFB_1、ZEN和DON 3种试纸条的胶体金溶液最适p H值分别为7.5、7.5和7.0,金标抗体量分别为4.2、7.2和9.6μg/ml,抗原包被量分别为1.0、1.4和0.8 mg/ml。检测卡的检测结果与仪器检测结果基本一致,重复性较好,与结构类似物及其他霉菌毒素无交叉反应,在室温条件下可以保存12个月。结论该三联检测卡操作简便、快速、准确、稳定,且能同时检测3种真菌毒素,在谷物的现场检测中有较好的应用前景。     

稻米中镉快速检测金标试纸条的研制

制备一种用于快速检测稻米中重金属镉的金标试纸条。将完全抗原Cd-iEDTA-BSA作为T线,羊抗鼠二抗作为C线,包被于硝酸纤维素膜上,纳米金颗粒标记的7E8G9单克隆抗体包被于金标垫上,组装成金标试纸条。试纸条的灵敏度为0.2μg/mL、重复性良好、与Hg~(2+)有较强交叉,最高共存浓度不得高于1.0μg/mL;与Zn~(2+)有一定交叉,最高共存浓度不得高于10μg/mL;与Cu~(2+)、Fe~(2+)、Ca~(2+)、Mg~(2+)、Al~(3+)、Pb~(2+)几乎无交叉:贮存期约为1年。试纸条检测稻米中镉与GFAAS结果一致。成功制备了金标试纸条,并应用于快速检测稻米中重金属镉。     

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.     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

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.