黑龙江省肉鸡养殖和屠宰加工环节中沙门菌调查

目的了解黑龙江省肉鸡养殖和屠宰加工环节中沙门菌污染状况。方法根据国家食品安全风险监测专项《肉鸡养殖及屠宰加工环节沙门氏菌专项监测工作手册》规定的操作程序,并参考国家标准GB 4789.4—2010《食品安全国家标准食品微生物学检验沙门氏菌检验》对黑龙江省4个地市3 766份肉鸡样品进行检验。结果 4大环节共检测样品3 766份,检出阳性样品339份,检出率为9.00%,孵化、养殖、屠宰到配送分销4个环节均检出沙门菌,检出率分别为2.82%(22/781)、2.14%(11/515)、13.84%(220/1 590)、9.77%(86/880)。其中,屠宰环节的8种样品中预冷池水样品沙门菌检出率最高,为35.42%(34/96)。检出的沙门菌分属于9个血清型,以肠炎沙门菌和印地安纳沙门菌的比例最高。结论黑龙江省肉鸡屠宰和配送分销环节中沙门菌污染较严重。屠宰环节阳性率最高,是重要的污染环节,其中预冷池水中沙门菌检出率最高,是屠宰过程中肉鸡污染沙门菌的主要环节。     

2012—2017年广西壮族自治区市售食品中沙门菌监测数据分析

目的 了解广西市售食品中沙门菌污染状况和特征,为减少污染和防控食源性疾病提供科学依据。方法 2012—2017年从广西14个市采集14类市售食品共60 174份,其中生鲜类食品5 712份,即食食品54 462份,按照GB 4789.4—2010《食品安全国家标准 食品微生物学检验 沙门氏菌检验》方法进行沙门菌检验。结果 生鲜类食品中生肉及生肉制品、生水产品及其制品、速冻米面制品、鲜蛋类沙门菌检出率分别为10.3%(399/3 883)、6.2%(50/806)、0.5%(2/440)、0.0%(0/583),即食食品中熟肉制品、餐饮食品、生食蔬菜及其制品沙门菌检出率分别为0.6%(58/10 175)、0.3%(39/14 721)、1.0%(5/489),焙烤及油炸类食品、饮料、水果及其制品均为0.1%,熟蛋制品、豆制品、冷冻饮品、调味品均未检出。生肉及生肉制品共检出51种血清型,德尔卑沙门菌为优势血清型(16.2%,70/432),主要在生猪肉中检出。即食食品共检出32种血清型,德尔卑沙门菌为优势血清型(14.5%,11/76),主要在熟肉制品中检出。结论 生鲜类受沙门菌污染最严重的食品是生畜肉和生禽肉,即食食品受沙门菌污染较严重食品是凉拌类食品。应加强从农场到餐桌的食品安全防控,减少食源性疾病的发生。     

济南市零售鸡肉中沙门菌污染状况及可移动黏菌素耐药基因分析

目的 了解2020—2021年济南市零售鸡肉中沙门菌的污染状况,并探究可移动黏菌素耐药基因（mcr）的携带情况。方法 2020年12月至2021年11月在济南市采集零售鸡肉样品260份,依据GB 4789.4—2016《食品安全国家标准食品微生物学检验沙门氏菌检验》对样品中的沙门菌进行分离鉴定,通过聚合酶链式反应（PCR）对分离株进行血清型鉴定和mcr基因筛选,使用微量肉汤法对mcr基因阳性株开展抗生素敏感性试验。结果 260份零售鸡肉样品中共检出阳性样品61份,污染率为23.46%(61/260),秋季污染率最高可达53.33%(32/60);共分离出沙门菌103株,56株为肠炎沙门菌,占比54.37%(56/103)。2株不同产地鸡翅样品来源的印第安纳沙门菌分离株检测出mcr-1基因,阳性率为1.94%(2/103)。2株mcr-1基因阳性印第安纳沙门菌分离株均为多重耐药株,其中1株可对碳青霉烯类和多黏菌素类在内的全部12类测试抗生素同时耐药。结论 2020—2021年济南市零售鸡肉中的沙门菌污染较为严重,秋季采集样品的污染率较高,肠炎沙门菌为优势血清型,检出携带mcr-1基因;同...     

2015—2021年湖州市食品中沙门菌污染与分子分型研究

目的 了解湖州市市售食品中沙门菌的污染状况,为预防与控制食源性疾病的发生提供依据。方法 采集2015—2021年5类1 463份样品按照GB 4789.4—2016《食品安全国家标准食品微生物学检验沙门氏菌检验》对沙门菌进行检验,对分离到的沙门菌进行血清分型、抗生素敏感试验和脉冲场凝胶电泳分子分型（PFGE）检测,结果用Excel、SPSS 19.0进行统计分析。结果 2015—2021年共检测5类1 463份食品样品,检出沙门菌菌株47株,总检出率为3.21%(47/1 463)。不同食品类别中生畜肉检出率最高,为6.61%(23/348)。共检出19种血清型的沙门菌,其中优势血清型为鼠伤寒沙门菌。不同食品中检出的沙门菌血清型有差别。对2019—2021年分离到的20株沙门菌进行药敏试验和PFGE检测,结果显示分离株对氨苄西林和四环素耐药性较强,耐药率分别为70%(14/20)和60%(12/20)。分子分型显示,经Xba I酶切后,19株沙门菌产生11个PFGE带型,多态性较高。结论 2015—2021年湖州市市售5类食品中均有检出沙门菌,其中两类为即食食品（中式凉拌菜和散装熟肉制...     

环介导等温扩增技术快速检测沙门菌

环介导等温扩增(loop-mediated isothermal amplification,LAMP)是一种在等温条件下高特异、高效、快速地扩增靶序列的DNA扩增新技术.以沙门菌(Salmonella spp.)为研究对象,根据其特异性的invA基因,设计了一套特异性引物对该基因进行了LAMP,同时优化了其反应条件,建立了沙门菌的LAMP快速检测技术.结果表明,LAMP的最佳反应条件为外引物浓度5 pmol/L、内引物浓度40pmol/L,Mg2 浓度6mmol/L,dNTP浓度0.8mmol/L,甜菜碱浓度0.8mmol/L,Bst DNA聚合酶8u,反应温度63℃,反应时间1 h.在此条件下,LAMP检测沙门菌DNA的敏感度达10fg/反应,且与其他常见的细菌无交叉反应.其对牛奶样品的检出量为102cfu/mL,适合于食品中污染沙门菌的快速检测.     

一起肠炎沙门菌引起的食物中毒检测及菌株同源性分析

检测食物中毒样品中致病菌,分析其同源性,为追踪污染源、明确病因诊断提供帮助,为控制和减少食物中毒提供依据。方法 荧光定量PCR快速筛检致病菌,参照GB 4789.4—2010《食品安全国家标准 食品卫生微生物检验 沙门氏菌检验》分离致病菌,全自动细菌鉴定仪鉴定致病菌,脉冲场凝胶电泳(PFGE)分析同源性。结果 从21份病人和从业人员粪便样品中检出8株肠炎沙门菌,9份食品样品中检出2份肠炎沙门菌,检出率分别为25.00%和6.25%;食堂用水及井水检测均未检出肠炎沙门菌等致病菌。荧光定量PCR法阳性率结果与GB 4789.4—2010方法一致。PFGE分型显示10株肠炎沙门菌的DNA条带图谱完全一致,相似性100%,聚类分析为同一型,表明菌株来自同一克隆系。结论 采用荧光定量PCR筛检能提示食物中毒样品中病原菌是否存在的信息,通过GB 4789.4—2010方法仔细寻找到目标菌,两法联合使用能快速、准确地检测出引起食物中毒的致病菌。运用PFGE对致病菌进行溯源,分析其亲缘关系,能追踪到菌株来源,有利于防止食物中毒的发生。     

PCR技术检测动物源性食品中沙门菌的应用研究

为快速准确检测动物源性食品中的沙门菌,将建立并优化的沙门菌PCR检测试剂盒应用于动物源性食品的检测,并于国标法进行了比较.对上海地区238份鸡蛋、685份原料牛奶、283份猪肉、314份牛肉和58份虾仁样品的沙门菌检测表明,PCR法的敏感性和特异性均为100%,与国标法的符合率亦为100%,且检测时间仅为2 d,较国标法大为缩短.该方法可用于动物源性食品中沙门菌的检测,并具有快速、特异、敏感等优点。     

LAMP法检测牛奶中金黄色葡萄球菌、鼠伤寒沙门菌和大肠杆菌O517:H

目的建立一种能快速准确检测牛奶中金黄色葡萄球菌(Staphylococcus aureus)、鼠伤寒沙门菌(Salmonella typhimurium)和大肠杆菌O517:H7(Escherichia coli O517:H7)的环介导恒温扩增方法(loop mediated isothermal amplification,LAMP)。方法以牛奶为研究对象,分别利用金黄色葡萄球菌nuc,鼠伤寒沙门菌invA和大肠杆菌O517:H7的rfbE保守基因设计LAMP特异引物,通过优化反应温度、时间等条件,建立检测牛奶中金黄色葡萄球菌、鼠伤寒沙门菌和大肠杆菌O517:H7的LAMP反应体系。并验证了本方法的特异性和灵敏度。结果 LAMP法对牛奶中金黄色葡萄球菌、鼠伤寒沙门菌和大肠杆菌O517:H7的灵敏度均为1.0×10~2拷贝/μL,比常规PCR灵敏度提高了10倍。金黄色葡萄球菌和大肠杆菌O517:H7的LAMP反应条件为60℃、30 min,鼠伤寒沙门菌为60℃、60 min。利用SYBR Green I染料在紫外光下可直接观察检测结果,金黄色葡萄球菌、鼠伤寒沙门菌和大肠杆菌O517:H7阳性样品均呈绿色;进一步利用荧光定量PCR仪可检测到对应的扩增曲线。通过牛奶样品模拟掺杂实验,验证了方法的实用性和可靠性。结论本研究建立的检测牛奶中金黄色葡萄球菌、鼠伤寒沙门菌和大肠杆菌O517:H7的LAMP方法具有特异性强、灵敏度高、操作简便等特点,可用于牛奶中相关致病菌的检测,对预防和控制3种致病菌的传染有重要意义。     

双重PCR检测生鲜猪肉中大肠杆菌O157∶H7和沙门菌方法的建立与应用

目的建立生鲜猪肉中大肠杆菌和沙门菌的双重PCR检测方法,并初步调查生鲜猪肉中大肠杆菌和沙门菌的污染情况。方法以大肠杆菌O157∶H7 rfb E基因和沙门菌inv A基因为靶基因设计引物。通过对单个基因PCR和多重基因PCR扩增进行特异性、敏感性试验以及优化反应体系,建立快速检测大肠杆菌和沙门菌的双重PCR法。在郑州市不同地区的综合性超市、冷鲜肉专卖店和农贸市场随机抽检144份生鲜猪肉样品,分别进行了PCR检测和常规微生物学检验。结果建立的双重PCR方法特异性好,抗干扰能力强,灵敏度可达到10 pg/μl。在144份样品中检测出大肠杆菌的样品数为10份,检出率为6.94%;检出沙门菌的样品数为13份,检出率为9.03%;大肠杆菌和沙门菌同时检出的有2份,占总样品的1.39%。结论初步建立了同步、简便、快速、灵敏地检测生鲜猪肉中大肠杆菌、沙门菌的双重PCR方法;生鲜猪肉中存在致病菌的污染问题,将威胁到食品安全和人体健康,不容忽视。     

杨凌及周边地区零售分割鸡肉中沙门菌污染状况及耐药和分型特征研究

目的研究陕西杨凌及周边地区零售分割鸡肉中沙门菌的污染状况及其药敏性、血清型和基于脉冲场凝胶电泳(PFGE)的基因型,为预警食源性沙门菌疾病暴发提供数据基础。方法采用GB 4789.4—2010《食品安全国家标准食品微生物学检验沙门氏菌检验》对陕西杨凌及周边地区采集的188份零售分割鸡肉中沙门菌进行分离和鉴定,并进行血清学分型。采用PFGE方法确定沙门菌DNA酶切电泳图谱,使用BioNumerics软件聚类分析电泳结果,确定沙门菌基因型。结果 188份零售分割鸡肉中共有34份(18.1%)样品检出沙门菌,农贸市场样品沙门菌检出率(24.6%,29/118)高于超市(7.1%,5/70)。鸡腿、鸡爪、鸡脖和鸡肝样品中沙门菌检出率高于鸡肠和鸡胗。34株沙门菌中共检出10种血清型,其中科瓦利斯沙门菌最为流行,高于德尔卑沙门菌和鼠伤寒沙门菌等,差异有统计学意义(P0.05)。分离株均对磺胺异噁唑、氯霉素、头孢噻呋和环丙沙星耐药,对甲氧苄啶/磺胺甲噁唑、萘啶酮酸、四环素、链霉素、氨苄西林和阿莫西林/克拉维酸的耐药率均在50%以上。34株沙门菌PFGE分型后可被分为11个簇,同一血清型菌株基本聚于同一大簇,同一时间、从相同市场采集的不同样品,其分离株PFGE型相似度均较高,表明分割鸡肉在加工或销售过程可能存在交叉污染。农贸市场分离菌株基因型多样性比较丰富。结论杨凌及周边地区零售分割鸡肉存在沙门菌污染,沙门菌血清型和基因型多样化,耐药菌株比例较高。     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.