可视化环介导等温扩增技术检测鸡鸭源性成分

目的建立生肉及熟肉制品中鸡、鸭源性成分的特异性基因LAMP可视化快速检测方法。方法根据鸡鸭物种特异性cytb、COX3基因的6个特异性区域设计LAMP引物,在反应前加入羟基萘酚蓝(HNB),在63℃条件下反应45 min;反应结果可以根据颜色变化直接判断,阳性为天蓝色,阴性为紫罗兰色。并对30个肉制品样品进行可视化LAMP和PCR方法平行检测。结果 LAMP方法的最低检出限为1 pg,特异性良好,同时对肉制品中目标物检测的检出限可达到0.01%。结论该方法用于肉制品中鸡鸭源性成分的快速检测,具有操作简单、无需贵重仪器、反应结果肉眼可观察、灵敏度高和特异性强等特点,适合于基层监管部门进行肉制品现场快速检测。     

实时荧光PCR在鉴别鸡精中鸡源性成分的应用研究

文章利用实时荧光PCR方法,以鸡的cytb基因为目的基因,设计了一套特异性的引物和探针,对鸡精中的鸡源性成分进行定性、定量分析研究.结果表明,该套引物和探针能特异性的检测鸡精中鸡源性成分;荧光PCR检测的灵敏度为0.002％ (W/W),检测时间为3h.此方法具有准确、快速、高效的特点,为食品中鸡源性成分的检测提供了新方法.     

实时荧光PCR技术快速检测食品中的牛源成分

目的:建立基于实时荧光PCR技术的食品中牛源性成分快速检测方法.方法:以牛线粒体细胞色素b为目的基因,设计特异性引物和探针,通过特异性、灵敏性实验,及模拟混合肉样和市售肉制品检测,对该体系进行验证.结果:该牛源荧光PCR检测体系具有很好的特异性及灵敏性,可检测1pg牛源DNA的存在,对于各模拟肉类样品中掺杂的牛源性成分,其检测限低至0.5％,且经市售加工食品验证具有较好的应用能力.结论:所建立的牛引物探针体系具有特异性好、灵敏度高,快速高效等优点,可用于对食品中牛源性成分的掺假鉴别检测.     

食品中鸡源性成分实时荧光PCR检测方法的建立

目的：建立基于实时荧光聚合酶链式反应技术的食品中鸡源性成分快速检测方法。方法：以鸡线粒体细胞 色素b为目的基因,设计特异性引物和探针,通过特异性、灵敏性实验及模拟混合肉样和市售肉制品检测,对该体 系进行验证。结果：该鸡源荧光聚合酶链式反应检测体系具有很好的特异性及灵敏性,可检测3.5 pg/μL鸡源DNA 的存在;经含鸡源成分的模拟混合肉样检测,证实体系抗干扰能力强;并且通过市售食品检测表明体系可用于定性 加工食品中的鸡源成分。结论：所建立的鸡源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 食品中鸡源性成分的掺假鉴别。     

实时荧光PCR法与环介导等温扩增法检测食品中动物源性成分的比较

目的比较实时荧光PCR(real-time PCR)法及环介导等温扩增(loop-mediated isothermal amplification,LAMP)检测食品中动物源性成分,为食品安全监管部门动物源性成分鉴定提供准确、高效的检测方法。方法采用实时荧光PCR法及LAMP法分别对市售肉及其制品进行牛、猪和鸡源性成分鉴定,并与标签明示的肉源成分比对,以准确性和时效性2个指标对上述2个方法进行评价。结果 Real-time PCR法检出4份样品与标签明示肉源不符,LAMP法检出5份样品与标签明示肉源不符,而16份样品中仅有1份样品2种方法检测结果不同。Real-time PCR法检测用时1.5 h,提取检测用DNA用时1.5 h,总用时3 h;而LAMP法检测用时45 min,提取检测用DNA用时20 min,总用时65 min。结论 LAMP法与Real-time PCR均具有较好的特异性、准确性,但LAMP法耗时短、成本低、操作简单,便于现场快速监督抽检。     

羊乳中牛乳成分的直接实时环介导等温扩增检测

根据线粒体保守序列选取牛、羊特异性引物,建立无需核酸提取的直接实时环介导等温扩增(LAMP)技术,用于羊乳中掺入牛乳成分的检测。结果表明,所建立的LAMP方法特异性好,对其他物种没有交叉反应及假阳性现象的发生,对牛、羊的检测灵敏度可达0.07 pg/μL和0.7 pg/μL,在掺假样品(即二元混合乳)中直接实时LAMP技术可检测到掺入1%的牛乳成分。通过对10种市售羊乳制品检测显示,直接实时LAMP方法与经DNA提取的实时LAMP方法检测结果一致。因此建立的直接实时LAMP技术无需核酸提取,样品经简单处理即可作为模板直接进行LAMP扩增,简化了样品前处理过程,缩短了检测时间,适用于羊乳制品中牛乳成分的快速检测。     

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。     

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。     

基于线粒体DNACOⅠ基因鉴别畜禽肉中鸡源性成分

为建立畜禽肉中鸡源性成分的快速检测方法,以线粒体DNA细胞色素C氧化酶亚基Ⅰ(COⅠ)基因序列为靶点,比较羊、牛、猪、兔、鸽、鹌鹑、鸡、鸭、鹅9种动物COⅠ基因的差异位点,设计筛选鸡特异性引物,进行常规聚合酶链式反应(polymerase chain reaction,PCR)和荧光定量PCR检测。结果表明:所设计的引物仅对鸡肉DNA模板有扩增条带和典型扩增曲线,且循环阈(cycle threshold,Ct)值为21.78,对其他动物DNA模板无扩增。方法特异性较强,灵敏度较高,达pg级,可以用于畜禽肉与肉制品中鸡源性成分的快速、有效、准确检测。     

环介导等温扩增法快速检测牛羊肉中的掺杂肉

面对肉制品掺假突发事件频发的现状,对动物源性成分快检方法需求迫切。在等温扩增方法基础上,开展了肉制品掺假鉴定方法研究。以猪、鸡、鸭线粒体细胞色素b基因为目的序列,采用软件Primer Explorer Version5,通过序列比对设计并筛选环介导等温扩增(Loop-mediated isothermal amplification, LAMP)的特异性扩增引物。通过反应体系优化建立猪、鸡、鸭源性成分的环介导等温扩增技术分析方法,对常见9种动物源性成分进行特异性分析,检出限达到0.001 ng/μL,高浓度牛、羊DNA不影响方法检出限。通过分析模板脱氧核糖核酸(Deoxyribonucleic acid, DNA)浓度与反应循环数的关系,建立牛羊肉产品中,阈值为1%的猪、鸡、鸭掺杂成分的LAMP快速检测方法,分析时间36 min。采用该方法对深加工模拟掺杂肉样本分析结果与现行国家标准方法结果一致。研究可为肉制品原材料、市售生鲜肉及加工肉制品的肉成分快速筛查提供解决途径。     

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.