北京地区牛、羊肉片中鸭、鸡、猪源性成分调查

建立生肉制品中鸭、鸡、猪源性成分的荧光PCR检测方法,对北京地区出售的牛、羊肉片进行成分调查。方法 合成检测鸭、鸡、猪源性成分的特异性引物和探针,建立实时荧光PCR检测方法,测定方法的特异性、灵敏度,在北京部分超市、农贸市场、餐馆采集牛、羊肉片进行成分调查。结果 所建立的实时荧光PCR方法对鸭、鸡、猪源性成分具有较好特异性,与常见食用肉类DNA在Ct 30以内无交叉反应;对混合肉中鸭、鸡、猪成分DNA的检出限是0.1%。北京市场上采集的86份牛、羊肉片中,30份检出上述成分,占34.9%;羊肉片的掺假率高于牛肉片;农贸市场采集样品掺假率明显高于超市和餐馆。结论 所建生肉制品中鸭、鸡、猪源性成分的检测方法简单、特异,对样品的检测结果显示,北京市售牛、羊肉中存在掺入鸭、鸡、猪肉的现象。     

利用PCR法检测熟牛肉的肉源性

本文旨在建立实时荧光PCR检测熟牛肉中牛、猪、马等动物源性成分的方法。通过对菏泽市市售熟牛肉进行采样检测,提取熟牛肉中总DNA后进行实时荧光PCR检测,确定Ct值,分析样品熟牛肉中牛、猪、马源性成分。通过检测DNA提取液(纯度1.6~1.7),便能满足实时荧光PCR的检测要求。本次采样检测的12批样品中,2批既检出牛源性成分又检出马源性成分,说明样本可能存在马肉掺假为牛肉的问题。     

2013年苏州地区肉及其制品掺假情况调查

了解苏州地区肉及其制品的掺假情况,通过对肉类种源与标签明示肉源进行比对,鉴别摻假食品,为加强食品标签管理提供依据。方法 运用自建的动物源性食品种源判定Taqman实时荧光PCR检测体系对苏州地区的肉及其制品进行种源判定,与标签明示肉源进行比对,鉴别摻假食品。结果 本次调查共检验涉及32个生产单位的90份样品,总不符合率为25.6%(23/90)。检测的44份牛肉及其制品中有12份与标签不符,8份用猪肉部分替代牛肉,1份以鸭肉部分代替牛肉进行销售;此外有3份不含有牛肉成分,存在猪、鸡、鸭源性肉类之外的肉类成分。共检测羊肉及其制品16份,有2份用鸭肉代替羊肉出售,3份羊肉样品中掺入了部分猪成分,其中1份样品还存在单个样品掺杂两种外源肉类的现象(猪源性和鸭源性)。检测猪肉及其制品19份,其中2份样品含有标签未注明的鸡肉成分。在所检测的11份混合肉类样品中有4份成分与标签不符,主要是以廉价的鸡肉取代/部分取代相对高价的牛肉和猪肉。结论 肉制品掺假情况明显,用猪肉、鸭肉部分代替牛肉和羊肉仍是主要的掺假手段,牛肉掺假样品主要是熟制牛肉制品,而火锅食用羊肉卷样品则是羊肉掺假高危品,开展肉制品摻假检测对规范肉制品市场具有积极意义。此外,3份未知种源成分的牛肉样品提示在现有检测基础上还需扩大检测范围,防患于未然。     

基于DNA条形码技术常见肉类掺假鉴别技术的研究

根据市场上常见的肉类掺假情况,本研究通过提取生鲜牛肉、羊肉、猪肉和鸭肉基因组DNA,按一定比例进行预混合,构建牛肉掺猪肉、羊肉掺猪肉、牛肉掺鸭肉和羊肉掺鸭肉4种掺假模型。通过引物COI-1和COI-2进行PCR扩增和测序比对,建立基于COI基因的动物源性食品的掺假判别方法。根据实验所得纯肉DNA提取率T实现DNA水平到肉水平掺假比例的换算。在肉的掺假水平上,引物COI-2检测效果较好,对牛-猪、羊-猪、牛-鸭和羊-鸭模型掺假物的检出限分别为5%、8%、1%和4%。对采集的28个批次的肉制品进行检测,结果表明:28个样品中89%的样品与产品标签标识的成分相符。建立的基于DNA条形码技术的检测方法可作为一种简单、快速、有效的分子鉴定技术,可以直接应用于研究物源性食品的种类和掺假鉴定。     

基于COI序列的DNA微条形码技术鉴别熟肉制品中11种肉掺假的研究

建立并优化了基于COI序列的DNA微条形码技术（mini-barcoding）检测熟肉制品中11种常见肉类掺假的方法。样品经超声与真空冷冻干燥处理,提取DNA模板和PCR扩增后,目标扩增物经切胶纯化后进行克隆测序,并将测序结果提交GenBank数据库Blast比对。筛选出适合猪、牛、羊、鸡、鸭、鸽子、马、驴、鹅、兔、鼠11种肉类的扩增的通用引物COI-A,对PCR扩增条件进行优化,并建立18个掺假模式,对低经济价值肉类（猪、鸡、鸭、马、驴、鼠）的掺入的最低比例进行考察。结果表明:11种熟肉的DNA经通用引物COI-A扩增后,其扩增效率均为100%,18个掺假模式中,牛肉和羊肉中掺入6种低经济价值肉类的最低检出比例为5%,而掺入鸡肉的最低检出比例为10%,而鹅肉、鸽子肉和兔肉的掺假模式中最低检出比例为10%;利用本方法检测30批次市售样品,发现有18批次的熟肉制品存在掺假情况。该方法前处理简单,灵敏度合适,重现性好,可作为高经济价值熟肉制品中掺假低经济价值肉类的有效检测方法。     

肉类掺假的分子生物学检测

针对Gene Bank中公布的牛羊猪鸡鸭线粒体细胞色素氧化酶亚基基因的特异性序列设计引物,建立了肉样的5种常见牛羊猪鸡鸭动物源性成分检测的PCR电泳法体系。采用大连宝生物的猪源牛源羊源鸡源性成分检测试剂盒和广州迪奥生物的鸭源性成分检测试剂盒,利用实时荧光PCR检测体系对河南省范围内几个大型超市的118批次牛肉样品的5种即猪牛羊鸡鸭动物源性成分进行了检测。结果显示:牛源性成分检出117批次检出率99.15%,猪源性成分检出10批次检出率8.47%,鸡源性成分检出7批次检出率5.93%,鸭源性成分检出1批次检出率0.85%,没有检出羊源性成分,其中熟肉制品掺杂其他源性成分的比例较高。与配料表对比掺假使假样品共9批次,总掺假率为7.63%。     

广东省牛羊肉及其制品中掺杂掺假情况的调查分析

目的对广东省内牛、羊肉及其制品中掺杂掺假情况进行风险监测,从而为监管部门的后续监督管理提供指导性意见。方法使用特异性引物和探针,对广东省市场上出售的牛、羊肉及其制品进行动物源性成分鉴定。并与标签明示肉源进行比对,确认掺假类别。结果共检验50份样品,其中牛肉25份,羊肉8份,混合肉类17份。检出10份掺假肉食品,总掺假率为20.0%。掺假样品均为牛肉制品,羊肉制品为未发现掺假情况。结论用猪肉和鸡肉进行肉类的掺假是目前主要的掺假手段。混合肉类制品在标签明示肉类成分方面比较混乱,部分样品检出标签未标示的肉类成分。进一步开展肉制品的掺假检测具有重要的社会意义。     

GNM C7-8实时荧光PCR系统对掺假肉制品中多种动物源性成分的同时检测

应用GNM C7-8实时荧光PCR系统,同时快速检测掺假肉制品中多种动物源性成分。将牛肉粉、驴肉粉、鸵鸟肉粉和羊肉粉4组不同肉粉中分别混入猪肉粉、鸭肉粉、马肉粉、鸡肉粉和狐狸肉粉中的2~3种肉粉,制备人工模拟掺假肉制品。通过GNM C7-8实时荧光PCR和ABI7500荧光PCR方法,对上述四种掺假肉制品进行多种动物源性成分检测和比较。结果表明,GNM C7-8实时荧光PCR方法与ABI7500荧光PCR方法从掺假肉制品中检测猪、鸭、马、鸡和狐狸5种成分的循环数一致,分别是31、31、29、32和25,但基于八模块设计的GNM C7-8实时荧光PCR方法能同时检测四种掺假肉制品中不同动物源性成分,检测时间更短。因此,GNM C7-8实时荧光PCR系统的八个模块能够独立运行,互不干扰,无交叉污染,能够实现对掺假肉制品中多种动物源性成分的同时快速检测,为肉制品掺假检测提供强有力的方法支持。     

基于锁式探针的荧光定量PCR技术快速检测肉制品中鸭源性成分

[目的]肉类掺假是食品行业面临的严峻挑战,其中羊肉和牛肉用鸭肉掺假较为常见。本研究主要目的是为检测掺假肉制品中的鸭源性成分提供一个新的检测方法。[方法]本研究根据鸭线粒体基因组16s rDNA中的特异性序列设计鸭源锁式探针和扩增引物,并结合荧光定量PCR技术,建立肉制品中鸭源性成分检测的新方法。[结果]基于锁式探针的荧光定量PCR技术检测肉制品中鸭源性成分的检测灵敏度达到70fg·μL~(-1)。[结论]本研究建立的基于锁式探针的荧光定量PCR检测鸭源性成分方法检测特异性强,灵敏度高,为肉类掺假鉴定提供了新的技术手段。     

应用PCR技术检测掺假肉类

目的建立5种动物源性成分的普通PCR检测方法,4种动物源性成分的实时荧光PCR检测方法,为食品安全服务。方法提取各肉制品的基因组DNA,合成PCR检测引物和荧光探针,优化反应条件和反应体系建立各动物源性成分的检测方法,分析市场上肉类掺假状况。结果建立了几种动物源性成分的检测方法,根据已建方法对保定辖区采集的样品进行检测,羊肉制品56份,掺假率为75%;驴肉制品15份,掺假率为6.7%;牛肉制品5份,掺假率为20%;兔肉制品2份,掺假1份。这些结果表明辖区市场上存在较多的肉类掺假问题,尤其是来自自由市场和烧烤摊的样品,掺假现象严重损坏了消费者的权益。结论建立的PCR检测方法获取DNA快速,检测灵敏度可以达到pg或fg级别,适用于大量肉制品的检测。     

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.