食品中小麦致敏成分的常规PCR检测方法的建立

建立了一种常规PCR方法用于检测一系列原料和加工食品中小麦致敏成分的DNA。针对小麦的ω-醇溶谷蛋白设计了一对大小为185 bp的引物。检出限为10 ng。该法能检测热加工食品中的小麦DNA,并具有良好的特异性,可作为食品无谷蛋白标识的检测方法。同时它弥补了免疫化学方法的不足,并为乳糜泻患者的食品安全提供保障。     

实时荧光PCR法测定婴幼儿谷类辅助食品中麸质过敏原成分

目的建立实时荧光PCR法检测婴幼儿谷类辅助食品中麸质过敏原成分的含量。方法样品加入淀粉酶液化后,采用试剂盒方法提取样品DNA,考察大麦Hordein基因、小麦Gliadin基因、黑麦Secl基因和燕麦Avenin基因检测方法的特异性、灵敏度和检出限,幵应用于检测实际样品。结果确定了实时荧光PCR反应体系条件,各个基因的检测方法具有特异性强且灵敏度高,检出限为0.1%。结论该方法操作简便,准确率高,适用于婴幼儿谷类辅助食品中麸质成分的检测。     

乳粉中阪琦肠杆菌的PCR检测

针对我国食品进出口和生产卫生的需要,使用以16 S rRNA基因为靶序列设计合成了一对可扩增282 bp的目的片段的引物,建立了检测阪琦肠杆菌的PCR方法.结果表明,阪琦肠杆菌PCR产物有282 bp的特异性片段,而金黄色葡萄球菌无此目的条带,证实该引物具有特异性.该方法快速、可靠、灵敏,特异性强,可用于食品中阪琦肠杆菌的检测.     

实时荧光PCR法检测奶制品中常见谷物成分

建立Taqman实时荧光PCR法对奶制品中掺加物大米、玉米、小麦、高粱、大麦等谷物源性成分的初筛检测体系。方法 以常见掺加物大米、玉米、小麦、高粱、大麦等谷物的叶绿体rbcL基因作为靶基因,通过BLAST软件比对,选择其同源保守区域设计引物和探针。经通用性、特异性、灵敏性试验对探针和引物可行性进行验证,并通过模拟含谷物奶粉及市售奶类制品检测对其实际检测能力进行验证。结果 所建立体系可扩增大米、玉米、小麦、高粱、大麦等常见的谷物掺加物的DNA提取物,与市售奶制品的主成分牛奶、羊奶以及其常见添加物香蕉、红枣、菠萝、草莓、西红柿、花生、大豆等动植物源性成分无交叉扩增(Ct＞35)。对小麦纯DNA提取物检出限为0.01ng。对分别掺加5种谷物成分的模拟奶制品检出限均可达0.5%,对市售的14份奶类食品中的谷类成分的检测结果均与食品标签相符。结论 本研究建立的Taqman实时荧光PCR体系具有通用、相对特异、灵敏、实用等优点,可用于奶制品中掺加或掺杂掺假谷物源性成分的快速定性检测。     

应用多重PCR检测食品中SARS病毒靶基因的初步研究

以分子生物学方法——聚合酶链式反应(PCR)技术为基础,初步探讨了食品中SARS病毒靶基因片段的多重PCR检测技术。根据GenBank公开发表的SARS病毒基因组cDNA序列,人工合成克隆特异性靶基因DNA片段,以此片段作为阳性对照,并将其添加到罐装蘑菇、牛肉干、大豆、鱼干等食品的cDNA中作为阳性样品,再根据世界卫生组织推荐的引物序列合成引物,进行单PCR与多重PCR检测分析。结果表明:以单PCR法获得了121bp、182bp及302bp3条靶基因片段;以二重PCR法获得了121bp+182bp、121bp+302bp与182bp+302bp的靶基因片段组合;以三重PCR法获得了121bp+182bp+302bp的靶基因片段组合。检测灵敏度的实验表明:182bp片段的模板DNA量在0.003ng以上时,单PCR都能扩出清晰的条带,而121bp的靶基因片段只有模板DNA量在0.03ng以上时,单PCR才能扩出清晰的条带。它们的二重PCR分析的灵敏度与相应的单PCR分析灵敏度相同。     

双重PCR熔解曲线峰快速检测食品中猪源性成分方法的建立

基于国际生命条码联盟(CBOL,the Consortium for the Barcode of Life)提出的barcoding技术所确定的序列区域,针对猪的线粒体COⅠ基因序列设计特异性引物。为了避免食品中PCR抑制剂的影响,本实验设置GCG(胰岛素受体)基因125bp的纯化片段为内参照,控制假阴性结果的出现。通过优化PCR反应条件,猪和GCG基因的特异性产物在79.2℃和75℃有特异性熔解峰。设置牛、羊、鸡、兔、鼠和空白对照,均无扩增。测序结果表明,该猪特异性引物的PCR产物含有245bp的核苷酸序列与GenBank中相应序列吻合;该方法检出限为0.001%。     

PCR检测食品中致敏原虾源性成分

目的 建立食品中致敏原虾源性成分的PCR检测方法。方法 选择虾的16S rRNA基因作为物种鉴定的特异性标记基因, 设计适合于PCR扩增的引物, 进行虾的16S rRNA基因特异性和灵敏性检测。结果 通过对14种虾、5种蟹、24种鱼、12种贝类以及章鱼等56种样品进行PCR检测, 结果表明, 可以很好地鉴别虾源性成分。为研究食品加工过程对检测灵敏度的影响, 以虾肉和鱼肉为代表, 进行133 ℃热处理30 min的过程, 检测灵敏度可达到在鱼肉粉中检出0.05%含量的虾源性成分。结论 该方法特异、灵敏、准确, 适于食品中致敏原虾源性成分的检测。     

食品中马源性成分的实时荧光PCR检测

针对马线粒体DNA细胞色素b基因设计特异性引物和探针,建立食品中马源性成分实时荧光PCR检测方法,并经特异性和灵敏度试验验证其可行性。结果表明:该体系可扩增马DNA片段,长度为127 bp,其他常见畜、禽肉成分均无法正常扩增。该体系的检测灵敏度为1.25 pg马DNA和质量分数0.001%马肉粉。经市售食品的检测验证,表明所建立的马引物探针体系具有特异性好、灵敏度高、快速、高效等优点,可用于对食品中马源性成分的掺假鉴别检测。     

肉食品中兔源性成分的PCR-mtDNA检测

以兔肌肉组织DNA为模板,利用PCR-mtDNA技术成功克隆出兔线粒体DNA细胞色素酶Ⅲ基因,其序列包括兔COⅢ基因的全序列784 bp。利用设计好的引物P3、P4,PCR扩增兔DNA的特异性片段为230bp。对PCR产物进行测序分析可知,其与已克隆兔的mtDNACOIII基因同源性达到100%。对筛选出的特异性引物P3、P4进行灵敏度试验,结果分析表明灵敏度约为0.001%。根据试验,对mtDNA技术用于兔源性食品检测进行研究,为检测肉食品中兔源性成分提供实用、有效的方法,为以后PCR-mtDNA在兔源性食品检测方面的应用提供理论依据。     

多重位点特异性PCR快速检测牛肉中常见掺假动物源性成分

目的:基于动物线粒体cytb基因的多态性位点,建立一种特异性多重PCR体系检测牛肉、猪肉和鸡肉的方法。方法:提取肉类的基因组DNA,利用不同物种mtDNA cytb基因序列的SNP位点的差异,设计特异性引物。进行多重PCR扩增,利用扩增产物片段大小不同,检测牛肉中常见的掺假动物源性成分。通过灵敏性试验,确定最低检测量。结果:实验设计的引物特异性良好,在同一反应体系中,在同一退火温度52℃条件下,牛肉DNA扩增后产生149 bp的特异性条带,猪肉DNA扩增片段为261 bp,鸡肉DNA扩增片段为554 bp,未发生非特异性扩增。且检测的最低浓度达到100 pg/μL,具有高度的灵敏性和适用性。结论:根据动物线粒体cytb基因的差异性位点,开发的多重PCR体系,可一次性地同时检测牛肉、猪肉和鸡肉,可快速、灵敏、高通量地分析食品中掺假动物成分的来源。     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

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

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.