氯唑西林可视化免疫亲和凝胶柱检测方法研究

为了建立氯唑西林(Cloxacillin,CLOX)可视化免疫亲和凝胶柱检测方法。实验采用活化酯法,将辣根过氧化物酶(HRP)与氯唑西林偶联,制得氯唑西林酶标抗原,并通过紫外光谱扫描鉴定表明CLOX酶标抗原合成成功。实验采用恒温振荡法,将溴化氰活化的琼脂糖凝胶分别与氯唑西林抗体、HRP抗体偶联制得氯唑西林抗体胶和HRP抗体胶,作为亲和凝胶柱的检测层与质控层。建立氯唑西林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4000、抗体胶稀释倍数为10、HRP胶稀释倍数为20、样品稀释液pH值为5.7、加样时间为60 s条件下,达到最佳工作状态。该方法检测限为25μg/L,特异性强,与哌拉西林、阿莫西林、氨苄青霉素、四环素、呋喃它酮、甲砜霉素、链霉素均无交叉反应,动物源食品实际样品中氯唑西林检出限为25μg/kg。该方法便捷、快速、可视化,适合作为高通量筛选氯唑西林的有效检测手段。     

可视化普鲁士蓝纳米酶免疫亲和柱快速检测植物源性食品中氯吡脲

目的 建立快速检测植物源性食品中氯吡脲的可视化普鲁士蓝纳米酶免疫亲和凝胶柱的检测方法。 方法 制备了类过氧化氢酶性质的普鲁士蓝纳米粒子。合成了氯吡脲半抗原及完全抗原，制备了氯吡脲多克隆抗体。制备了普鲁士蓝纳米酶标记抗原、琼脂凝胶闭合胶体、抗体胶和辣根过氧化物酶抗体胶，组装了普鲁士蓝纳米酶可视化免疫亲和凝胶检测柱、建立了检测方法、测试了凝胶检测柱的特异性，检测了四种实际样品，得到方法检出限。 结果 合成的普鲁士蓝纳米粒子呈立方体形状，分布均均集中，粒径约为145.68±12 nm，能够催化TMB和 H2O2混合溶液显色，具有类过氧化氢酶性质。制备的氯吡脲多克隆抗体半抑制率(50% inhibiting concentration, IC50)为为2.35 ng/mL，抗血清效价最高为1：72000倍。凝胶检测柱的最佳组装条件为普鲁士蓝纳米酶标记抗原稀释1500倍，氯吡脲抗体胶稀释20倍、HRP抗体胶稀释30倍，凝胶检测柱的检出限为5 μg/L，四种实际样品的检出限为20 μg/kg，针对化学结构相似的五种农药具有良好的特异性。 结论 此方法具有便捷快速及灵敏的特点，可以作为植物源性食品中氯吡脲的快速检测方法。     

呋喃它酮代谢物可视化凝胶柱快速免疫检测方法研究

本研究建立了兽药呋喃它酮代谢物(Furaltadone metabolites,AMOZ)的免疫亲和凝胶柱检测新方法,并用于动物源性食品中呋喃它酮代谢物残留的可视化快速检测。整个检测在一个标准的1 mL固相萃取(SPE)柱中进行,柱中包含两层:一个结合了呋喃它酮代谢物特异性抗体的凝胶检测层和一个结合了辣根过氧化物酶(HRP)抗体的凝胶质控层。将样品提取液与酶标抗原预混合后加入到检测柱中,基于抗原抗体的竞争结合反应和辣根过氧化物酶的酶促反应,根据检测柱的检测层颜色的深浅和有无来定性,半定量检测呋喃它酮代谢物的含量。整个检测过程可以在10 min内完成,该凝胶检测柱的检测限为20μg/L;牛肉、鲷鱼、鸡肉、虾肉、猪肉、鱿鱼、鸡肝和黄花鱼等动物源性食品中呋喃它酮代谢物的检测限为3μg/kg。该方法准确度高、特异性好、检测步骤简单,适用于大量样品中呋喃它酮代谢物残留的快速检测。     

恩诺沙星可视化凝胶柱快速免疫检测方法研究

建立一种动物源性食品中兽药恩诺沙星可视化凝胶柱快速免疫检测新方法。采用活化酯法制备恩诺沙星与辣根过氧化氢酶(HRP)的偶联物作为酶标抗原。整个检测在一个标准的1 m L SPE固相萃取柱中进行,柱中包含两层:一个结合了恩诺沙星特异性抗体的凝胶检测层和一个结合了HRP抗体的凝胶质控层。将样品提取液与酶标抗原预混合后加入到检测柱中,基于抗原抗体的竞争结合反应和辣根过氧化物酶的酶促反应,根据检测柱的检测层颜色的深浅和有无来定性半定量检测恩诺沙星的含量。该凝胶检测柱的检测限为5μg/L,整个检测过程可以在10 min内完成,猪肉、牛肉、鸡肉、鱼肉、虾肉和牛奶等动物源性食品中恩诺沙星检测限为100μg/kg。该方法具有准确、灵敏、特异性好、操作简便快速、成本低等优势,适合动物源性食品中恩诺沙星残留的快速筛查。     

量子点标记免疫亲和凝胶柱快速检测动物组织中恩诺沙星

目的:建立一种检测动物组织中残留的兽药恩诺沙星(ENR)的量子点标记免疫亲和凝胶柱快速检测新方法。方法:将恩诺沙星特异性抗体偶联到溴化氢活化的琼脂糖凝胶上,制备抗体胶,将抗体胶装入标准的1mL SPE固相萃取柱制成恩诺沙星免疫亲和凝胶检测柱。采用混合酸酐法制备恩诺沙星包被抗原(ENR-OVA),采用活化酯法将ENR-OVA偶联到水溶性量子点(QDs)上制备荧光信号探针QDs-OVA-ENR。将待测样品和荧光信号探针QDs-OVA-ENR分别加入检测柱中,基于抗原抗体的竞争结合反应,样品中的恩诺沙星和荧光信号探针QDs-OVA-ENR竞争结合检测柱中抗体。通过目测检测柱体的荧光强弱,定性半定量检测恩诺沙星的含量。结果:该量子点标记恩诺沙星免疫亲和凝胶检测柱的检测限(LOD)为2μg/L,对食源性动物组织样品的检测限为20μg/kg。检测过程不超过5 min。结论:该方法操作简便,灵敏度高,检测时间短,结果易于判断,可满足食源性动物组织中恩诺沙星残留的现场快速检测要求。     

乳制品中三聚氰胺的免疫亲和凝胶柱检测方法

为建立用于检测乳制品中三聚氰胺的免疫亲和凝胶柱检测方法,本研究采用活化酯法制备三聚氰胺酶标抗原,将三聚氰胺抗体、HRP抗体分别与溴化氰活化的琼脂糖凝胶偶联制备相应的抗体胶作为检测层和质控层,方法检测限为200μg/L。选取牛奶、奶粉、发酵乳等乳制品进行检测,测得所检样品中三聚氰胺的检测限为1 mg/kg。该方法具有良好的特异性,除与环丙氨嗪存在一定的交叉反应外,与其他3种结构类似物和6种常用兽药没有交叉反应。该检测方法操作简便,结果判断容易,整个检测过程约15 min,可用作三聚氰胺现场快速检测的有效手段。     

ELISA法测定热加工食品中的丙烯酰胺

该研究建立了热加工食品中丙烯酰胺的间接竞争ELISA检测方法.首先用戊二醛法合成丙烯酰胺-BSA免疫抗原,注入兔体内以产生抗丙烯酰胺多克隆抗体.结果显示,在包被抗原为1.5μg/mL,抗体稀释度为1∶16000倍的优化条件下,间接ELISA法检测范围为50μg/L～1280μg/L,IC50为检测限为350μg/L,最低检测限为50μg/L.加标回收率为92.6%～95.5%.该检测方法准确快速,特异性强,适用于热加工食品中丙烯酰胺的快速检测.     

量子点荧光猝灭免疫亲和凝胶检测柱检测番茄酱中罗丹明B的研究

目的:本研究根据抗原-抗体特异性识别反应和荧光共振能量转移(fluorescence resonance energy transfer,FRET)的原理,构建一种基于量子点(Quantum dots,QDs)的新型荧光猝灭免疫亲和凝胶检测柱检测番茄酱中罗丹明B(Rhodamine B,RB)残留。方法:通过罗丹明B的单克隆抗体与溴化氢活化琼脂糖凝胶-4B偶联制备分析物抗体胶,设计单检测层的凝胶检测柱。基于抗原抗体的特异性结合反应,并利用罗丹明B和量子点之间的静电引力作用,构建一种新型的荧光猝灭免疫亲和凝胶检测柱。通过优化抗体添加量、量子点稀释倍数、孵育时间以及上样量等参数,最终实现番茄酱样品中罗丹明B的快速灵敏检测。结果:当1.0 g溴化氢活化的琼脂糖凝胶添加2.0 mg罗丹明B单克隆抗体,量子点溶液稀释3000倍,孵育时间控制在50 s,罗丹明B上样量为3.0 mL,该荧光猝灭免疫亲和凝胶检测柱针对罗丹明B的方法检测限(limit of detection,LOD)能够达到最小值1.0 μg/L。样品分析结果表明,该方法针对番茄酱样品中罗丹明B的检测限为5.0 μg/kg,并且与HPLC方法测定的结果表现出很好的一致性。结论:该方法操作简便,灵敏度高,检测时间短,结果易于判断,可以满足番茄酱中罗丹明B的现场快速检测的要求。     

呋喃它酮代谢物5-甲基吗啉-3-氨基-2-恶唑烷酮单克隆抗体的制备、鉴定与胶体金免疫层析试纸条的研制

目的:制备5-甲基吗啉-3-氨基-2-恶唑烷酮(AMOZ)单克隆抗体,并建立AMOZ胶体金试纸条检测方法.方法:AMOZ与对醛基苯甲酸反应生成半抗原CP-AMOZ,将CP-AMOZ与BSA、OVA偶联制备完全抗原.免疫小鼠后制备腹水型抗体,ELISA检测抗体效价与其对CP-AMOZ半抑制浓度(IC50)和最低检测限(LOD),并检测抗体的特异性.胶体金与单抗偶联,同时在NC膜上包被完全抗原、兔抗鼠多抗分别作为检测线和质控线,制备免疫层析试纸条,测定试纸条的灵敏度与特异性.结果:成功制备CP-AMOZ-BSA、CP-AMOZ-OVA完全抗原及抗CP-AMOZ的单抗,抗体效价为1∶1.6×105,对CP-AMOZ IC50为0.86μg/L,LOD 0.07 μg/L,与其他硝基呋喃类药物代谢物及其衍生物均无交叉反应.制备的胶体金试纸条灵敏度5 μg/L.结论:成功合成了CP-AMOZ的完全抗原,免疫小鼠后制备了特异性强的单抗,并以此为基础研制出敏感、特异的胶体金快速检测试纸条.     

微型氯霉素免疫亲和色谱柱的制备和测定

将氯霉素多克隆抗体与琼脂糖凝胶偶联,制备了对氯霉素有特异性吸附作用的微型氯霉素免疫亲和色谱柱,并对色谱柱进行了评价。该微型氯霉素免疫亲和色谱柱的动态柱容量为52720μg/L,富集极限可以达到100ng/L,对氯霉素的回收率达到98.5%以上,可以重复使用2次。该色谱柱可以有效消除基质的影响,提高检测的灵敏度,可应用于乳制品等食品中氯霉素残留的样品快速前处理。     

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.     

Review of techniques to manufacture micro-hydrogel particles for the food industry and their applications

Microgels are ‘soft’ microscopic cross-linked polymeric particles that are being increasingly exploited in a variety of industries for rheology control, encapsulation and targeted delivery. They are valued because of the ability to tune their functionality to address specific applications in oil recovery, coatings, drug delivery, cosmetics, personal care and foods. Food microgels are typically biopolymer hydrogels in the form of microspheres, nanospheres (also called nanogels), spheroids and fibres. The utilisation of engineered microgels in foods has so far been limited, despite their great potential to address several needs in the food industry, including: satiety control, encapsulation of phytonutrients and prebiotics, texture control for healthier food formulations (e.g. reduced fat products), and targeting delivery to specific areas in the digestive tract. We review the scientific and patent literature on the utilisation and manufacturing methods for producing microgels with an emphasis on micro-hydrogels for food applications.     

12—A CRITIQUE OF SOME HYPOTHESES RELATING TO THE HETEROGENEITY OF THE HIGH-SULPHUR PROTEINS OF WOOL

Joubert and Burns prepared a large number of fractions from the high-sulphur proteins of wool and estimated their molecular weights and amino-acid compositions. Their data have been re-examined in order to look for statistically significant interrelations between amino acids and between the proportion of various amino acids and molecular weight. Statistical analysis of the data is also used to examine the credibility of some hypotheses concerning the mechanism of keratin biosynthesis and to provide further evidence for the existence of families of proteins within the high-sulphur fractions of wool.     

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.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of     

The Latest Data about Development of Chinese Printing Industry in 2013

In the 2014 China（Shanghai）International Printing Week,Director Wang Yanbin released the latest data about development of Chinese printing industry in 2013.According to statistics,in 2013,the total output value of Chinese printing industry exceeded 1trillion Yuan for the first time,reaching 1.03985 trillion Yuan.There were 105,000 printing enterprises in China,employees were 3.415 million.The total asset was 1.06247 trillion Yuan;     

The State Council Issued "Directory of Government Approved Investment Projects(2013 Edition)"

正On December 2nd,2013,the State Council issued the notification of"Directory of Government Approved Investment Projects(2013 Edition)"(hereafter referred to as"notification").It is pointed out in the"notification"that in order to further deepen reforms in investment systems and administrative examination and approval systems,simplify administrative procedures and delegate powers to lower levels,earnestly     

China textile machinery: taking off in progress

正Among the 1600 exhibitors who take apart in the ITMA ASIA+CITME2014 2/3 are Chinese manufactures.If the numerous figures failed to attract your attention,the increase of quality should draw your focus.To adopt the demand of developing textile machine market,domestic textile machinery enterprises now follow the slogan of"technology drives development"to enhance product competitiveness.Our domestic sellers will showcase product ranging from spinning,weaving,dyeing and printing,     

Top Ten News of China's Paper Industry 2013

On December 24th, 2013, the meeting on the selection of top 10 news of China＇s paper industry 2013 sponsored by 〈China Paper Newsletters〉 was held in Beijing. The yearly selection of the top l0 news, which began in 2000, has become a brand activity widely recognized in the industry thanks to the support from the authorities at all levels and public participation.