酶联免疫吸附法检测动物源性食品中氨苯砜残留

应用间接竞争酶联免疫吸附技术,建立了一种快速检测动物源性食品中氨苯砜残留的方法,并对其各项技术参数进行了评价。结果显示,该方法的半数抑制浓度IC50为0.369μg/L,对鸡肉、猪肉样本的检测限为0.2μg/kg,对鸡蛋、蜂蜜样本的检测限为2μg/kg,对牛奶样本的检测限为0.6μg/L;样本添加回收率为78.2%~104.0%,变异系数为5.2%~13.5%;对实际样本的检测结果与液相色谱-串联质谱法基本一致。该方法操灵敏度高、快速准确,适用于动物源性食品中氨苯砜残留的快速检测。     

食用油中苯并(a)芘的快速检测研究

采用间接免疫法结合显色反应快速检测食用油中苯并(a)芘,在抗体与磁珠上苯并(a)芘抗原结合的基础上,通过辣根过氧化酶连接苯并(a)芘二抗进行间接免疫反应。结果表明:优化的免疫磁珠反应条件为苯并(a)芘抗体用量4μg,辣根过氧化酶用量100μg,免疫反应温育时间60min;方法的线性范围为0. 5 pg/m L～500 ng/m L,检出限为0. 12μg/kg,定量限为0. 5μg/kg,加标回收率为89. 3%～100. 1%。方法具有良好的特异性和稳定性,符合食品污染物现场快速检测的基本要求。     

酶联免疫法检测食品中乳酸链球菌素

建立了酶联免疫吸附法来检测乳制品、肉制品和含乳饮料中的乳酸链球菌素含量。在抗乳酸链球菌素多克隆抗体的基础上,建立间接竞争酶联免疫吸附法。所建立的间接竞争ELISA方法的灵敏度为0.1μg/mL,标准曲线范围为0.1～62.5μg/mL,乳制品的检测限为1.0μg/mL,肉制品的检测限为0.5μg/g,样本的添加回收率范围在80%～120%之间,变异系数<20%。所建立的间接竞争ELISA方法及制备的相关试剂盒具备准确、快速、简便的优点,能够满足乳制品、肉制品和含乳饮料中乳酸链球菌素含量的检测要求。     

呋喃它酮代谢物的可视化免疫亲和凝胶柱检测分析

为了建立一种用于检测动物源性食品中呋喃它酮代谢物(AMOZ)的可视化免疫亲和凝胶柱检测方法,利用对醛基苯甲酸(CPA)对AMOZ进行衍生处理得到衍生物CPAMOZ,制备CPAMOZ完全抗原,并通过免疫小鼠获取CPAMOZ多克隆抗体,使用间接ELISA法对抗体的效价及特异性进行测定。实验采用恒温振荡法将溴化氰活化的琼脂糖凝胶分别与CPAMOZ抗体、HRP抗体偶联制得CPAMOZ抗体胶和HRP抗体胶,作为亲和凝胶柱的检测层与质控层。建立AMOZ可视化免疫亲和凝胶柱分析方法,确定了该方法在酶标抗原的稀释倍数为5000、HRP胶稀释20倍、CPAMOZ抗体胶稀释15倍的条件下,达到最佳工作状态。实验结果表明CPAMOZ多克隆抗体效价为1:64000,IC_(50)值为2.19μg/L,具有良好的灵敏度及特异性。建立的AMOZ可视化免疫亲和凝胶检测柱方法检测限为4μg/L,动物源实际样品中AMOZ的检测限为2μg/kg。该方法快速便捷,符合我国高通量筛选食品中AMOZ的要求。     

胭脂红酸人工抗原合成及多克隆抗体的制备

为了快速高效检测食品中胭脂红酸含量,本研究通过羟基二咪唑法制备了胭脂红酸人工抗原;通过免疫新西兰大耳白兔获得了胭脂红酸抗血清,经硫酸铵沉淀法分离纯化获得抗胭脂红酸多克隆抗体;利用棋盘滴定法检测了抗体效价,并探究了溶液pH值、离子强度和有机溶剂对ELISA反应的影响,优化出最佳ELISA反应条件;在最佳反应条件下,建立了胭脂红酸的间接竞争ELISA抑制曲线。紫外光谱扫描结果显示,免疫抗原(CA-BSA)和检测抗原(CA-OVA)均与载体蛋白成功偶联;经分离纯化获得的胭脂红酸多克隆抗体效价为1:16000;检测抗原最佳浓度为1μg/m L、ELISA反应最适缓冲液为pH7.4、含50mmol/L Na~+且无甲醇的磷酸盐缓冲液;间接竞争ELISA标准曲线的线性范围为7.8～1150ng/mL,检测限为1ng/mL,灵敏度IC_(50)值为95.2ng/mL。本研究为开发CA快速检测试剂盒对食品中胭脂红酸含量的大量快速测定奠定了基础。     

双抗夹心酶联免疫吸附法检测荞麦过敏蛋白

提取制备荞麦过敏原蛋白(TBt)并免疫动物,分别制备鼠多克隆抗体和兔多克隆抗体,建立了双抗夹心酶联免疫吸附检测法(ELISA)用于检测食品中的荞麦过敏原。SDS-PAGE结果表明,纯化的TBt纯度达到98%以上,鼠抗血清效价为1∶6400。建立的双抗夹心ELISA法对荞麦过敏原蛋白的最低检测限为0.16μg/m L,线性范围为0.16~16μg/m L。并采用建立的双抗夹心ELISA法对市场出售的15种食品中荞麦过敏成分进行了检测。结果显示,该方法对绝大多数食品中的荞麦过敏原都有很好的特异性及灵敏性,说明该法可用于食物过敏原的诊断及食品中微量荞麦过敏成分的检测。     

盐酸克伦特罗残留酶联免疫吸附(ELISA)检测方法的研究

建立了间接ELISA检测盐酸克伦特罗的方法,并对其参数进行了分析计算。在该检测方法中,抗盐酸克伦特罗(CL)抗体最适稀释度为1∶1000,羊抗兔酶联抗体(HRP-IgG)的最适稀释度为1∶1500。该检测方法的检测灵敏度可达0·1046μg/L,生物检测限为1·452μg/L,线性检测范围为7·26~90·75μg/L。     

河豚毒素直接竞争ELISA检测方法的研究

本研究应用直接竞争ELISA法对河豚毒素(tetrodotoxin,ITX)进行快速检测.用过碘酸钠氧化法合成酶标记抗原HRP-OVA-TTX),用直接ELISA方法对合成的酶标记抗原进行鉴定表明其与抗TTX单克隆抗体具有特异性反应.在此基础上建立了包被单抗的直接竞争ELISA方法.该方法对TTX的检测限可达到1.1μg/L,IC50为20.4μg/L,线性范围3.3～137μg/L,批内变异系数小于6.25%,批间变异系数小于7.34%.对鲫鱼的肌肉组织添加TTX标准品,回收率为65%～93.2%,变异系数为9.41%～12.77%.     

特布他林残留酶联免疫检测方法的建立

采用自主制备的特布他林特异性抗体建立特布他林残留的间接竞争酶联免疫(ELISA)检测方法,对该检测体系的灵敏度、准确度、精密度、特异性进行测定,并将该检测方法与高效液相色谱(HPLC)法进行对比分析。结果表明:特布他林残留检测体系的检测范围为1～100ng/mL,灵敏度为0.47ng/mL,检测限为1ng/mL,回收率80%～99%,与盐酸克伦特罗、硫酸沙丁胺醇的交叉反应率分别为94.9%、93.9%,与盐酸莱克多巴胺及肾上腺素的交叉反应率小于0.01%。采用HPLC法进行沙丁胺醇残留的检测时,其检测范围为10～200μg/mL,检测限为1μg/mL,回收率为79.2%～94.8%。ELISA法与HPLC法相比,灵敏度较高、特异性强、检测结果准确度相近,但在检测结果稳定性方面逊于HPLC法。     

基于上转换纳米材料与磁分离的荧光免疫分析方法检测食品中酪胺

实验基于间接竞争反应原理,结合上转换纳米材料与磁分离技术,建立分析食品中酪胺荧光免疫的方法,并进一步应用于肉制品、水产品及发酵制品中酪胺的检测。最佳实验条件为12 μg抗体偶联NaYF4Yb,Tm上转换纳米材料制备信号探针,70 μg包被原偶联磁性聚苯乙烯微球制备捕获探针,信号探针添加量为70 μL,感应探针添加量为100 μL,孵育时间为30 min。方法线性范围为0.1～100.0 μg/L,检测限为0.05 μg/L,该方法可特异性识别酪胺,与其他生物胺及其结构类似物无交叉反应。样品添加回收率为86.44%～101.62%,变异系数小于10%,该方法适用于食品中酪胺的快速检测。     

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.