利用荧光定量PCR技术鉴别畜禽肉中猪源性成分

以猪特异性基因序列为靶位点设计特异性引物,以常见畜禽肉包括猪肉、羊肉、兔肉、牛肉、鸽肉、鹌鹑肉、鸡肉、鸭肉、鹅肉等参考动物肌肉DNA为模板,进行荧光定量PCR扩增,建立猪源性成分荧光定量PCR检测方法;并将猪肉DNA模板浓度进行8个梯度稀释,检测其灵敏度。结果显示,该方法能够有效对猪源性成分进行快速检测,具有较强的特异性,灵敏度较高,可快速准确地鉴别畜禽肉中猪源性成分。     

荧光定量PCR方法检测畜肉食品中鸭源性成分

目的 建立一种快速、特异、灵敏的鸭源性成分检测方法。方法 本研究以鸭线粒体基因全序列为靶位点设计引物和探针, 进行荧光定量PCR扩增, 建立鸭源性成分检测方法; 以常见畜禽肉包括羊肉、牛肉、鸡肉、鹅肉、猪肉、兔肉、马肉、鹿肉等参考动物物种作特异性检测; 以50 mg/kg羊肉DNA作为稀释液对鸭肉DNA进行梯度稀释, 做灵敏度检测。结果 该方法能够有效对鸭源性成分进行快速检测, 具有较强的特异性, 灵敏度较高(可达0.1 μg/kg)并且羊肉成分的存在对鸭肉灵敏度检测没有影响。结论 该方法特异性强, 灵敏度高, 可以快速、准确检测畜肉食品中含有的鸭源性成分。     

聚合酶链式反应快速检测畜肉食品中鸭源性成分

目的：建立一种快速、特异、灵敏的鸭源性成分检测方法。方法：以鸭细胞色素C氧化酶Ⅲ（COⅢ ）基因序列为靶位点设计引物,进行聚合酶链式反应扩增,建立鸭源性成分检测方法;以常见畜禽肉,包括羊肉、牛肉、鸡肉、鹅肉、猪肉、兔肉、马肉、鹿肉等参考动物物种进行特异性检测;以50 mg/kg羊肉DNA作为稀释液,对鸭肉DNA进行梯度稀释,检测灵敏度。结果：该方法能够有效的对鸭源性成分进行快速检测,具有较强的特异性,灵敏度较高（0.1 μg/kg）,且羊肉成分的存在对鸭肉灵敏度检测没有影响,可以快速、准确检测畜肉食品中掺杂的鸭源性成分。     

荧光定量PCR方法检测肉制品中鳄鱼源性成分

针对鳄鱼色素细胞b基因序列设计特异性引物,建立一种快速、特异、灵敏的鳄鱼源性成分检测方法。以常见羊肉、牛肉、猪肉、鸡肉、鸭肉、鱼肉、虾肉为参考动物物种作特异性检测,并经检出限和灵敏度实验验证其可行性。结果表明：该方法能够有效对鳄鱼源性成分进行快速检测,具有较强的特异性,鳄鱼组分DNA的检出限可达0.001 ng/μL,灵敏度可达0.01 %。通过加工肉制品的检测验证,该方法拥有特异性强、灵敏度高的特点,可以用于加工肉制品中鳄鱼源性成分的检测。     

基于线粒体16SrRNA基因鉴别畜禽肉中5种动物源性成分

目的:建立一种快速、特异、灵敏的动物源性成分检测方法。方法:以线粒体16S r RNA基因序列为靶位点设计特异性引物,以常见畜禽包括羊、牛、猪、兔、鸡、鸭、鹅、鸽、鹌鹑等参考动物为研究对象,提取肌肉组织DNA,进行PCR扩增,设计筛选羊肉、牛肉、猪肉和兔肉特异性引物对,并进行引物特异性研究。结果:选择的特异性引物能够有效地对包括羊肉、牛肉、猪肉、兔肉以及鸡肉在内的5种动物源性成分进行快速检测,方便简洁。结论:该方法可以快速、准确地检测畜禽肉中羊肉、牛肉、猪肉、兔肉和鸡肉成分。     

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。     

肉制品中羊源性成分的定性和定量检测

通过检测肉制品中DNA的来源进行动物源性检测是打击鲜肉及加工肉制品制假掺假的重要技术手段。依据GB/T 25165—2010《明胶中牛、羊、猪源性成分定性检测方法 实时荧光PCR法》合成用于TaqMan 实时荧光聚合酶链式反应的引物和探针,利用鲜肉及加工肉制品进行羊源性成分定性和定量检测方法研究。首先利用12 种不同动物鲜肉组织的DNA检测方法的特异性,然后以羊源DNA梯度稀释液为模板进行灵敏度实验,最后在加工肉制品中检测方法的适用性和定量检测能力。结果表明：此方法具有羊源性成分检测特异性,对其他动物来源的鲜肉DNA均无扩增信号,可以检出羊肉和猪肉混合样品中0.1%的羊肉;方法灵敏度高,可以检出10 pg的羊源DNA;方法适用性广,可以对加工肉制品（羊肉干）进行羊源性成分的定性和定量检测。     

肉制品中猪肉源成分的Proofman-梯型熔解温度等温扩增检测

建立一种基于Proofman探针（proofreading enzyme-mediated probe cleavage）的梯型熔解温度等温扩增（ladder-shape melting temperature isothermal amplification,LMTIA）方法检测肉制品中的猪肉成分。选取猪细胞核中的特异性基因PRLR为靶基因,设计LMTIA引物和Proofman探针。通过优化反应体系,对所建立的方法进行特异性、灵敏度和最低检测限结果评价。结果表明：所建立的Proofman-LMTIA方法可在30 min内完成检测;相对于从鸡肉、鸭肉、牛肉、羊肉、猫肉、狗肉、玉米淀粉、红薯淀粉、木薯淀粉、绿豆淀粉、小麦粉中提取的基因组DNA,可特异性检测猪基因组DNA;检测灵敏度为1 ng/μL,对人工模拟的混合肉样中猪肉的最低检测限为0.1%。所建立的Proofman-LMTIA方法对猪肉成分有较好的特异性,能够快速、准确检测出肉制品中的猪肉成分,可对猪肉掺假进行快速检测。     

Taqman探针荧光聚合酶链式反应实时同步鉴定动物源性食品中猪肉、鸡肉源性成分

目的:建立一种能实时同步检测动物源性食品中猪肉源性和鸡肉源性成分的Taqman探针双重荧光聚合酶链式反应(polymerase chain reaction,PCR)方法,应用于动物源性食品的成分掺假快速检验。方法:分别依据猪和鸡的种间保守基因(Cytb)序列设计、合成特异性引物及不同荧光标记(FAM、HEX)的Taqman探针,建立可同步检测动物源性食品中的猪源性和鸡源性成分的Taqman探针双重荧光PCR方法。结果:所建立的Taqman探针双重荧光PCR检测方法特异性强,仅对猪、鸡成分有扩增;灵敏度高,最低检测到猪源、鸡源DNA的含量分别为0.02、0.10 ng;抗干扰性强,当DNA混样中猪源、鸡源性成分含量在2%以上水平时,所建立的混合检测体系均能对DNA混样给出正确判断。结论:所建立的混合检测体系具有高特异性、高灵敏度,能够适用于动物源性食品中猪肉、鸡肉成分的同时快速检测。     

实时荧光PCR方法检测食品中痕量荞麦成分

目的：建立一种快速、特异、灵敏的荞麦成分检测方法。 方法：针对荞麦内转录间隔区ITS(internal transcribed spacer)和5.8S rRNA基因序列设计一对PCR引物及探针,建立实时荧光PCR检测方法;以同源性(27个荞麦属相关物种)及非同源性(食品中常见的栽培型植物)参考植物物种作特异性检测;以50mg/kg小麦DNA作为稀释液对荞麦DNA进行梯度稀释,做灵敏度检测。 结果：该方法能够有效对荞麦成分进行快速检测,具有较强的特异性,灵敏度较高(可达0.1μg/kg)并且小麦成分的存在对荞麦灵敏度检测没有影响。结论：该方法特异性强,灵敏度高,可以快速、准确检测食品中含有的痕量荞麦成分。     

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.