可视化膜芯片技术检测常见食源性过敏原成分

目的 建立包括鱼、虾、鸡、鸭、花生、核桃、小麦以及大豆过敏原成分的基因膜芯片技术, 实现对这几种食源性过敏原的同步可视化检测。方法 针对常见食源性过敏物质的成分特异性基因或者过敏原蛋白基因设计特异性的带生物素标记的引物和探针。采用反向斑点杂交(reversedot blot, RDB)结合多重聚合酶链式反应(multiplex polymerase chain reaction, MPCR)技术, 最终通过化学显色直观显示检测结果, 实现对多种食源性过敏原的同步可视化检测。结果 所建立的可视化基因膜芯片方法准确性强, 通过单目标物以及多目标物特异性实验, 显示本方法仅对鱼、虾、花生、核桃、大豆等靶标食源性过敏原有特异性反应, 非靶标物检测均为阴性; 通过制备不同质量浓度比的模拟样品考核方法的灵敏度, 经检测, 方法检测灵敏度可达0.1%(质量分数)。结论 所建立的方法可达到可视化、快速、准确地鉴别食品中鱼、虾、花生、核桃、大豆等常见食源性过敏原。     

胶体金免疫层析法快速检测食用油中黄曲霉毒素残留

为建立用于快速检测粮油样品中黄曲霉毒素药物残留含量的胶体金免疫层析检测试剂,我们采用免疫竞争法,将抗黄曲霉毒素单克隆抗体-胶体金复合物包被在微孔中,并将人工合成的黄曲霉毒素抗原包被在硝酸纤维素膜(NC膜)表面作为检测线(T 线)。待测样品中的黄曲霉毒素残留物将与NC膜上的黄曲霉毒素抗原竞争结合胶体金标记的抗黄曲霉毒素单克隆抗体,并以颜色直观显示检测结果。检测食用油样品时,灵敏度可达到0.5μg/L,仅需20 min。实验证明该检测试剂具有较高的灵敏度及很好的特异性,操作便捷,稳定可靠,可作为黄曲霉毒素残留现场监控的有效快速筛检手段。     

双抗体夹心ELISA法测定食物中花生过敏原蛋白成分

通过建立双抗体夹心ELISA法测定食物中花生过敏原蛋白成分,为进出口食品花生过敏原成分检测和由花生导致的食物过敏性疾病的预防提供技术基础.提取花生总蛋白,免疫小鼠制备抗花生总蛋白的多克隆抗体,用该抗体包被酶标板,并用生物素标记该多抗,从而建立双多抗体夹心ELISA法;自制花生总蛋白标准品并检测该方法的灵敏度,同时检测15种食品中是否含有花生蛋白成分.成功地研制出双抗体夹心ELISA法检测食品中花生过敏原蛋白成分,具有特异性,其最低检出限为8ng/mL,标准曲线在8 ng/mL～125 ng/mL范围内线性良好;13种食品检测结果与食物过敏原标签标注内容相符,而2种标示不详的食品检测结果均呈现阳性.     

时间分辨免疫荧光法测定食物中花生过敏原成分

目的:建立双抗体夹心时间分辨荧光免疫法[Time-resolved Fluoroimmunoassay(TRFIA)]测定食物中花生过敏原蛋白成分,为进出口食品中花生过敏原成分检测和由花生导致的食物过敏性疾病的预防提供技术基础。方法:提取花生蛋白,免疫小鼠制备抗花生总蛋白的多克隆抗体,用该抗体包被酶标板,并用生物素标记该多抗作为捕捉抗体,Eu3+标记的链酶亲和素和以β-二酮体为主的增强液等试剂,建立双抗夹心TRFIA方法,检测该方法的灵敏度,同时用于13种食品中花生过敏原蛋白成分检测。结果:初步地研制出双抗体夹心TRFIA法检测食品中花生过敏原蛋白成分,具有特异性,和其最低检出限为0.1ng/mL,标准曲线在0.1～160ng/mL范围内线性良好;11种食品检测结果与食物过敏原标签标注内容相符,而2种标示不详的食品检测结果均呈现阳性。     

克氏原螯虾新型过敏原血蓝蛋白的鉴定及性质研究

以克氏原螯虾为研究对象,鉴定血蓝蛋白的理化性质及其过敏原性。酶联免疫吸附试验结果表明:6份甲壳类过敏患者血清与克氏原螯虾血淋巴发生特异性IgE反应,利用离心和柱层析方法从血淋巴中分离纯化到目的蛋白。SDS-PAGE分析显示纯化的目的蛋白由6个亚基(依次为68,72,76,82,84和88 ku)组成,采用兔抗凡纳滨对虾血蓝蛋白多克隆抗体的免疫印迹试验证实目的蛋白为血蓝蛋白。免疫印迹试验结果显示,纯化的血蓝蛋白与甲壳类过敏患者血清出现了特异的杂交显色条带,表明血蓝蛋白具有IgE结合活性。与克氏原螯虾主要过敏原(原肌球蛋白)相比,血蓝蛋白的糖含量为1.99%,热稳定性好,pH稳定性及对胃蛋白酶的耐受性不如原肌球蛋白,但比原肌球蛋白更耐胰液消化。综合血清学及理化性质分析结果,提示血蓝蛋白是克氏原螯虾的1种新型过敏原。     

虾过敏C57／BL6小鼠动物模型的建立

目的：建立C57／BL6小鼠虾过敏动物模型及其腹腔肥大细胞过敏模型。方法：运用虾蛋白粗提液免疫致敏C57／BL6小鼠,采用Western Blot鉴定致敏小鼠血清中特异性lgE和lgG1抗体;收集小鼠腹腔致敏肥大细胞（PMC）,运用虾不同的过敏原组分诱导PMC体外定向释放组胺,HPLC和荧光酶标仪法检测组胺释放水平。结果：Western Blot结果显示致敏小鼠血清IgE和IgGl与相对分子量为36ku的原肌球蛋白反应率分别为57．1％和74．1％,与80ku过敏原的反应率均为42．9％,与21ku过敏原的反应率分别为42．9％和28．6％。HPLC和荧光酶标仪法检测PMC定向释放组胺的结果无显著差异,36ku的原肌球蛋白定向诱导组胺的释放率最高,分别为18．52％和21．59％,80ku和21ku蛋白次之,表明36ku的原肌球蛋白是C57／BL6小鼠的主要虾过敏原,21ku和80ku蛋白是次要过敏原,这与人类虾过敏的状况相一致。结论：C57／BL6小鼠是一种有效的虾过敏动物模型,其腹腔肥大细胞是一种可行的检测和评价食物过敏原的细胞模型。     

胶体金免疫层析法快速检测磺胺嘧啶残留

本实验用胶体金标记磺胺嘧啶多克隆抗体包被在胺体金垫上,磺胺嘧啶与牛血清白蛋白偶联物和羊抗兔二抗抗体分别包被在硝酸纤维素膜(NC)上作为检测线(T线)和质控线(C线),制成免疫层析快速检测试剂条,用于快速检测组织等样品中的磺胺嘧啶残留量.T线与待测样品中所含磺胺嘧啶竞争结合胶体金标记的磺胺嘧啶多克隆抗体,并通过胶体金显色直接观察检测结果.检测猪肉等组织试样时,灵敏度最低值可达到20 ng/mL,只需3～5 min.本试剂条具有较高的灵敏度及特异性,操作简单,快速,结果稳定可靠,可作为磺胺嘧啶残留现场监控的有效筛检手段.     

中国对虾蛋白致敏小鼠模型构建及主要过敏原的双向电泳联合质谱鉴定

目的:构建中国对虾蛋白致敏小鼠模型并研究关键过敏原。方法:采用液氮研磨结合裂解液裂解对虾肌肉提取蛋白浸出液,用不同剂量的中国对虾蛋白和弗氏佐剂的混合液腹腔注射诱发ICR小鼠致敏,采用间接ELISA方法检测小鼠血清中过敏原特异性IgE和IgG1水平在激发期不同时间点的变化,并观察致敏小鼠行为评分,建立动物致敏模型;利用双向电泳分离虾蛋白,并与阳性血清免疫印迹,从而通过质谱分析其主要过敏原。结果:3组不同剂量的虾蛋白浸出液都能使小鼠出现不同程度的过敏症状,且剂量越高过敏反应越显著;其中,高剂量组(1.0 mg)小鼠血清特异性IgE和IgG1抗体含量显著升高(P0.05),出现瘙痒、嘴角红肿等现象,过敏症状最显著。通过双向电泳联合质谱鉴定发现,能与阳性血清反应的蛋白有两种,一种蛋白分子质量为40.2ku,等电点分别为6.0和6.2,经比对为精氨酸激酶;另一种蛋白分子质量为35.8 ku,其等电点为4.6,经比对为原肌球蛋白,通过Mascot数据库分析比较得到这两种蛋白质的氨基酸序列。结论:中国对虾蛋白可引起小鼠过敏反应,其主要过敏原为原肌球蛋白和精氨酸激酶,其中精氨酸激酶可能存在不同蛋白质修饰的两种形式。     

一种快速检测食用油中黄曲霉毒素B1的胶体金试剂板的研制

为建立用于快速检测粮油样品中黄曲霉毒素B1药物残留含量的胶体金免疫层析检测试剂,采用免疫竞争法,将抗黄曲霉毒素B1单克隆抗体-胶体金复合物包被在微孔中,并将人工合成的黄曲霉毒素B1抗原包被在硝酸纤维素膜(NC膜)表面作为检测线(T线).待测样品中的黄曲霉毒素B1残留物将与NC膜上的黄曲霉毒素B1抗原竞争结合胶体金标记的抗黄曲霉毒素B1单克隆抗体,并以颜色直观显示检测结果.检测食用油样品时,灵敏度可达到0.5 μg/L,仅需20 min.试验证明该检测试剂具有较高的灵敏度及很好的特异性,操作便捷,稳定可靠,可作为黄曲霉毒素B1残留现场监控的有效快速筛检手段.     

生物膜干涉法检测花生蛋白与花生过敏患者血清IgE的结合能力

探索基于生物膜干涉技术对花生蛋白与花生过敏患者血清中免疫球蛋白E（immunoglobulin E,IgE）的结合能力进行检测的方法。利用链霉亲和素（streptavidin,SA）标记的传感器、生物素化的羊抗人IgE抗体、花生过敏患者血清池以及花生蛋白建立了一种测定花生蛋白与花生过敏患者血清IgE结合能力的新方法,优化检测条件为抗体1∶100稀释后线下固化20?min,血清1∶10稀释后过夜结合,完成传感器修饰。在线洗基线后用质量浓度为1?mg/mL的花生蛋白与传感器结合3?600?s,解离120?s。利用该法对不同热加工后花生蛋白与患者血清IgE的结合能力进行评估,并与常用的酶联免疫吸附实验（enzyme linked immunosorbent assay,ELISA）检测进行比较。结果表明,本方法可以直接评估过敏原蛋白与血清IgE的结合能力,与ELISA结果相关系数达到0.91。热加工中,油炸处理提高了花生蛋白的IgE结合能力,水煮和烘烤降低了花生蛋白的IgE结合能力,且去壳热加工比带壳热加工花生的蛋白的IgE结合能力更强。     

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.