快速检测沙门氏菌的荧光免疫试纸的研制

研制一种基于低噪声激发式荧光沙门氏菌免疫层析检测试纸条,用于沙门氏菌快速、高敏、兼顾定性及精准定量的检测。采用低噪声激发式荧光染料作为标记,采用免疫层析技术,制备靶向于沙门氏菌的免疫层析试纸条。检测时,采用专用便携式低噪声激发式荧光扫描仪分别扫描质控线和检测线,以检测线荧光强度检测值实现样本的定性及定量检测,并对免疫层析试纸条各项性能进行评价。低噪声激发式荧光沙门氏菌免疫层析检测试纸条制备成功,免疫层析试纸条性能检测结果显示,该试纸条特异性强、灵敏度高、检测限可达到0.5×10~3 CFU/mL,是一种新型快速高效稳定的检测方法。该免疫层析试纸条可适用于食品及病理样本中沙门氏菌初筛和即时检测。     

荧光微球免疫层析法定量检测牛乳中酪蛋白

目的研究用荧光微球免疫层析法定量检测牛乳中的酪蛋白。方法本文以酪蛋白为抗原,免疫新西兰大白兔制备抗酪蛋白的多克隆抗体,将纯化后的多克隆抗体通过EDC介导法与荧光微球进行偶联,将滤纸、样品垫、结合垫、NC膜和吸水纸组装成试纸条,用此荧光微球免疫层析法定量检测牛乳中的酪蛋白。结果试纸条在25 min内就能判定结果,最低检测限为100 ng/mL,该方法与BSA、OVA均无交叉反应,具有很好的特异性。检测酪蛋白浓度为100.0、500.0、1000.0 ng/mL的样品,试纸条的批内回收率分别为(89.03±5.2)%、(93.47±6.9)%和(91.2±7.8)%,批间回收率分别为(87.69±6.2)%、(92.73±8.3)%、(89.82±8.5)%。结论初步建立了一种快速、方便、高灵敏度的荧光微球免疫层析方法用以检测牛乳制品中的过敏原——酪蛋白。     

胶体金免疫层析法检测食品中花生过敏原蛋白成分

建立一种简易快速胶体金免疫层析法(GICA)用于检测食品中花生蛋白成分.采用柠檬酸三钠还原法制备胶体金颗粒、标记抗花生蛋白成分的抗体,制成免疫层析测试条.食品中花生蛋白成分与测试条上金标记抗体结合后沿着硝酸纤维素膜移动,与膜上的固相抗体结合形成肉眼可见的红色线条.自制花生抗原标准品并检测该方法的灵敏度,同时检测19种食品中是否含有花生蛋白成分.结果表明:GICA测试条与花生蛋白抗原呈特异性反应.检测自制的花生抗原标准品的灵敏度可达50ng/mL,用GICA试条检测了19种食品中,其中13种食品标签上标注含有花生过敏原成分的食品检测结果均呈阳性,4种食品标签上标注不含花生过敏原成分的食品检测结果均呈阴性,而2种食品标签上没有标注过敏原成分的食品检测呈阳性.     

牛奶过敏原检测方法研究进展

牛奶是八大食物致敏原之一,能引起严重的过敏反应。如何实现食物中牛奶过敏原的快速,准确筛检已成为食品安全领域关注的焦点。牛奶主要过敏原为酪蛋白、α-乳白蛋白、β-乳球蛋白,其检测方法有电泳法、色谱法、酶联免疫实验(ELISA)、传感器、基于质谱的蛋白质组学(LC-MS/MS)、聚合酶链式反应技术(PCR)等。本文就其检测方法的原理和应用进行综述,旨在为食品中牛奶过敏原的检测提供技术方向,以便保障牛奶过敏患者的安全。     

胶体金免疫层析法快速定量检测猪肝中喹乙醇残留

本文研究了胶体金免疫层析试纸条快速定量检测猪肝中喹乙醇残留的方法。利用胶体金免疫层析技术,制备了喹乙醇胶体金试纸条,检测了其特异性,并建立了T/C比值法进行定量检测猪肝中喹乙醇的残留。制备的试纸条可以在15min内完成定性和定量检测,与卡巴氧、乙酰甲喹和3-甲基-喹噁啉-2-羟酸几乎无交叉反应。当肝中喹乙醇质量浓度在1~200ng/mL范围内,试纸条有较好的线性关系,最低检测限为6.83ng/mL。阴性加标实验结果表明,喹乙醇浓度在25、50、100ng/mL时,试纸条的回收率在90.9%~105.0%之间。     

金标免疫层析法检测黄曲霉毒素B1的方法

应用金标免疫层析法（GICA）研制的金标免疫试纸条对食品中黄曲霉毒素B1的检测，来确立该方法的各项技术指标。结果表明：方法的最低检测限：2．5ng／mL；金标免疫试纸条在4℃环境下可稳定10个月以上；与类似毒素AFB2、AFG2的交叉反应率分别是7，14％、6，25％；检测时间小于15min；GICA与ELISA方法的符合率达90％以上。该方法简便、快速，有较高的灵敏度，重复性好，特异性强，能定性或半定量检测食品中的黄曲霉毒素B1含量。     

基于定向标记抗体的虾原肌球蛋白量子点免疫层析方法的建立及应用

目的 利用量子点定向标记的单克隆抗体,建立竞争荧光免疫层析方法快速检测食品中虾原肌球蛋白(tropomyosin, TM)。方法 使用杂交瘤细胞株免疫Balb/c小鼠,从小鼠腹水中制备得到单克隆抗体,将氨基化量子点通过具有抗体Fc端生物亲和性的重组蛋白共价固定于抗体Fc端。以量子点定向标记抗体作为检测抗体,以南美白对虾中的TM作为检测靶标,基于竞争法原理组装免疫层析试纸条。在对条件参数进行优化后,应用于市售食物样品中TM的检测。结果 所建立方法的灵敏度为0.96μg/mL (%P=50%),检出限为0.15μg/mL(%P=20%),检测结果与文献中报道的相当。试纸条批内差和批间差的变异系数分别为6.81%～8.86%和8.27%～14.67%,均小于15%,在可接受范围之内。同时试纸条显示出了良好的特异性与准确性,实际样品的检测结果与过敏原标签一致。结论 本研究所建立的荧光免疫层析试纸条检测方法适用于TM的快速、高效检测。     

胶体金免疫层析法快速检测猪肉及牛奶中磺胺二甲嘧啶残留

目的:以胶体金为标记物,根据竞争抑制免疫层析原理,建立一种快速检测猪肉及牛奶中磺胺二甲嘧啶残留的方法.方法:采用柠檬酸三钠法制备40nm胶体金.电镜鉴定后标记磺胺二甲嘧啶多克隆抗体:磺胺二甲嘧啶半抗原-OVA和羊抗兔二抗分别包被在硝酸纤维素膜上,金标抗体喷涂在玻璃纤维垫上,制成免疫层析快速检测试纸条.结果:所建立的检测体系方法检出限为1 μg/L,将该法与高效液相色谱法(HPLC)对比检测猪肉和牛奶样品,在试纸务的检测范围内,与HPLC法检测结果一致性好,从而验证了该方法的有效性.结论:通过消除基质影响,成功检测到猪肉及牛奶中的磺胺二甲嘧啶残留.该方法灵敏度高,样品前处理简便、快速,整个检测过程可在10min内完成.该方法适用于动物源性食品中磺胺二甲嘧啶残留的大批量现场检测.     

质谱技术在食物过敏原检测中的研究进展

食物过敏是当前食品安全领域比较突出的问题,相应的过敏原检测方法研究也越来越受重视。相比于传统的免疫学检测方法,质谱技术在检测加工后以及复杂基质中的食物过敏原中,具有高通量和高灵敏性等优点,被广泛应用于食物过敏原的检测。本文主要从定性和定量2方面介绍了质谱技术在食品过敏原检测中的研究进展。相关研究对牛乳、鸡蛋、小麦和榛子(坚果类)等主要食物过敏原均有涉及。在定性研究中,以肽质量指纹图谱法和肽碎片离子鉴定法为主,鉴定食物中的过敏原蛋白。在定量研究中,通过标记/无标记技术,也能够实现对微量的目标蛋白进行相对/绝对定量。质谱技术应用于食物过敏原检测中,将有助于提升过敏原检测能力,降低食物过敏安全风险。     

基于比色和荧光双信号检测戊唑醇的免疫层析试纸条的构建

基于Au@PDA核壳纳米粒子和其对量子点荧光淬灭效应,制备了一种双信号读取模式的免疫层析试纸条,可用于定性或定量检测果蔬中戊唑醇的含量.研究了纳米金和抗体复合物的制备、试纸条传感元件的载量和缓冲液等因素对试纸条检测灵敏度的影响.在最优条件下,采用比色检测模式时,所构建双信号戊唑醇试纸条,其肉眼定性检测限为1μg/mL;...     

乳及乳制品中抗生素类兽药残留快速检测技术

抗生素等兽药残留物分析是个十分复杂的技术问题，介绍了按不同目的和要求对抗生素等兽药残留物进行的分级检测的策略，并对目前国内外正在应用或开发的快速检测技术进行了介绍。     

The development of an efficient and rapid enzyme linked fluorescent assay method for the detection of Listeria spp. from foods

Conventional isolation methods, including the Health Products and Food Branch (HPFB), Health Canada method used for the isolation and identification of Listeria species and Listeria monocytogenes from foods and environmental samples, can take a week or more to complete and are usually labor-intensive. This has led to the development of various rapid methods which attempt to generate results comparable to standard methods but in a reduced time-frame with less hands-on operation. Our previous work with rapid detection systems indicated that the recommended enrichment protocols failed to grow the Listeria to detectable levels in a reliable and consistent manner.In the present study, a novel enrichment protocol is described and consists of samples being pre-enriched in Palcam broth (incubated at 35 degrees C for 26 h), enriched in UVM 2 (30 degrees C for 26 h) and then plated and analysed by a rapid detection kit, with results being generated after 52 h of incubation.In total, 200 naturally contaminated samples were analysed by both the HPFB standard method and the Palcam method. The results showed that the Palcam method is comparable to the HPFB method. Further analysis involved a rapid detection system, which applies ELISA techniques and automation in an enzyme-linked fluorescent assay (ELFA) system. This system, referred to as the Vitek Immuno Diagnostic Assay System or VIDAS, can identify Listeria to the genus or species (L. monocytogenes) level.In this comparison, an additional 324 naturally contaminated samples were analysed by both the Palcam and ELFA methods. The sensitivity and specificity of the ELFA method were 98.1% and 97.0%, respectively, while the efficiency was 97.5%. False-negative and false-positive rates were 1.9% and 3.0%, respectively. These results show that the ELFA method (when using the Palcam method for pre- and secondary enrichment) was efficient and gave reliable results after 52 h of incubation, and met Health Canada's criteria for approval as a rapid method.     

食品中甲醛分析方法研究进展

食品中的甲醛问题引起了人们的高度重视,检测食品中的甲醛至关重要。食品中的甲醛主要来源于食品自身代谢合成、人为添加和环境污染。甲醛的分析方法包括样品前处理方法和甲醛检测方法。根据不同的食品种类,需要选择合适的样品前处理方法,具体方法包括:浸泡法、蒸馏法、超声法和蛋白沉淀法。甲醛检测方法分为常规检测方法和快速检测方法。常规检测方法主要有分光光度法和色谱法。分光光度法包括乙酰丙酮法、变色酸法、AHMT法、间苯三酚法和盐酸苯肼法。目前甲醛快速检测方法成为了研究热点,示波极谱法、试纸法、生物传感器法等快速检测方法得到快速发展。     

食品及空心胶囊中铬测定的前处理方法的研究

目的探究不同前处理方法对食品及明胶空心胶囊中铬测定结果的影响。方法采用湿消解法、微波消解法、干灰化法进行样品前处理,石墨炉原子吸收法进行测定。结果 3种前处理方法对标准物质的检测结果除干灰化法奶粉的检测结果略低外,均在标准值规定的范围内;3种前处理方法对8种样品的检测结果的统计学分析显示,湿消解法与微波消解法之间差异无统计学意义(P0.05),而干灰化法与其他两种消解方法之间差异有统计学意义(P0.05)。结论本试验所用的3种前处理方法均可用于食品中铬的检测;湿消解法的实用性较强,对于任何基质的样品都可以进行很好的消解;干灰化法的空白值低,方法操作简单,但检测结果偏低;微波消解法样品消解时间短、空白值较低、试剂用量少、重现性好。     

植物生长调节剂在植物源性食品中残留量检测 技术的研究进展

近年来,植物生长调节剂的应用不断增多。植物生长调节剂和其他农药一样,也有一定的毒性,研究表明植物生长调节剂残留在植物、水果、蔬菜中,短期内影响不大,但长期食用会对人体产生负作用,造成人体内代谢失调,从而引发各种疾病。我国对于植物生长调节剂类没有明文规定禁止使用,因此加强植物源性食品中植物生长调节剂残留量的快速有效检测,对保证食品安全,促进人类健康及社会经济发展都具有重大的现实意义。本文对近几年国内外植物源性食品中植物生长调节剂残留量的前处理方法及检测技术进行了详细的分析,同时对未来植物源性食品中植物生长调节剂残留量的检测技术发展进行展望。     

智能电位滴定仪测定烘炒食品中过氧化值

采用智能电位滴定测定烘炒食品中的过氧化值.样品粉碎过筛,溶剂浸泡、挥发后,油脂采用智能电位滴定仪测定其中的过氧化值含量.分析了烘炒食品前处理的影响因素,及仪器的最佳分析条件.结果表明,根据样品类别,称重1～5 g,采用石油醚Ⅰ为溶剂,智能电位滴定仪滴定,铂电极,样品采取动态电位滴定,空白采用等体积滴定.实验快速、结果准确、是一种方便快速高效的仪器检验方法.     

Potential efficacy of processing technologies for mitigating crustacean allergenicity

ABSTRACT

Crustacean allergy has become a growing food safety concern at a global scale. In the past decades, various food processing approaches have been employed to develop food products with reduced allergenic potential. Thermal treatment can dramatically influence the allergenicity of crustaceans by either reducing or enhancing their allergenic potential. Maillard reaction, enzymatic and acid treatments have shown to be promising in mitigating crustacean allergenicity. Recently, novel processing technologies, namely high-pressure processing, high-intensity ultrasound, irradiation, pulsed ultraviolet light and hurdle technology have attracted special attention from the researchers and the food industry professionals owing to their benefits over the conventional methods. In this context, this review paper provides an updated overview of the current knowledge on how different food processing methods induce structural changes of crustacean allergens and, subsequently, influence their allergenic potential. Data on prevalence and clinical relevance of crustacean allergy are presented, as well as, the molecular characterization of crustacean allergens and the main analytical methods for their detection in processed foods.     

固相萃取-高效液相色谱法同时测定食品中12种合成色素

目的建立一种固相萃取-高效液相色谱法同时测定食品中12种合成色素(柠檬黄、亮黑、日落黄、诱惑红、坚牢绿、丽春红2R、荧光素钠、丽春红3R、专利蓝、金黄粉、荧光桃红、孟加拉玫瑰红)。方法改进GB/T5009.35—2003《食品中人工合成着色剂的测定方法》试样处理方法,使用100～200目聚酰胺固相萃取柱对样品进行净化、浓缩,以甲醇-0.02 mol/L乙酸铵溶液为流动相,梯度洗脱,多波长检测定量。结果线性范围分别为:柠檬黄、亮黑、日落黄、诱惑红、坚牢绿、丽春红3R、专利蓝、金黄粉、荧光桃红0.1～30.0μg/ml,丽春红2R 1.0～30.0μg/ml,荧光素钠0.5～30.0μg/ml,孟加拉玫瑰红2.0～30.0μg/ml。12种合成色素的线性关系良好,相关系数0.999 3～0.999 9,回收率89.1%～100.4%,RSD 1.6%～8.2%,检出限为0.58～3.0 mg/kg。结论该方法简便、快捷、灵敏度高、准确率强、重现性好,适用于食品中12种合成色素的定量分析。     

PCR Detection of Listeria monocytogenes in different Food Products compared with the mini-VIDAS LMO System and the Standard Procedure ISO 11290-1

The presence of Listeria monocytogenes in 225 natural samples, including different food types, was investigated by three methods: (i) culture-based standard procedure ISO 11290-1, (ii) mini-VIDAS (Vitek Immuno Diagnostic Assay System) LMO, an enzyme linked fluorescent assay (ELFA) commercially available, and (iii) PCR using a previously established procedure. Identification of isolates recovered from the standard method and mini- VIDAS, on Oxford and PALCAM selective plates, was carried out using the API-Lis system and also by PCR, using L. monocytogenes specific primers. In all, 65 samples (64 meat products and one smoked salmon) were positive with any of the three procedures assayed. Taking into account the results based on PCR identification, the standard culture-based method found 22 and the mini- VIDAS 23, while PCR detected 60 positive samples in a total of 225 food samples. For comparative purposes, a set of “known positive samples” was established as reference that included 33 natural samples from which L. monocytogenes isolates (identified by specific PCR) had been recovered. The mini-VIDAS and ISO 11290- 1 methods were equally sensitive. Compared to them PCR was clearly the more accurate and efficient procedure for detection of L. monocytogenes in food. Moreover, it showed no false negative results. The PCR approach can be completed in 48 working hours, and because of its specificity might eventually be cheaper than the other two procedures. Consequently we recommend PCR for routine detection of L. monocytogenes in food.     

Analysis of phytosteryl and phytostanyl fatty acid esters in enriched dairy foods: a combination of acid digestion, lipid extraction, and on-line LC-GC

Qualitative and quantitative methods for the analysis of intact phytosteryl/phytostanyl esters in enriched dairy products with substantial amounts of protein and fat were established. Lipids were extracted after acid digestion in order to achieve a complete extraction of the esters. The extracted lipids were separated via liquid chromatography on a normal phase, and the fraction containing the phytosteryl/phytostanyl esters was subsequently transferred on-line and analyzed by means of capillary gas chromatography. The applicability of the method was demonstrated for the analysis of intact phytosteryl/phytostanyl fatty acid esters in enriched yogurt, cheese-based spread, and milk. The approach enables the determination of individual phytosteryl/phytostanyl esters as well as of their total contents and provides detailed information on the distributions of esterified phytosterols/phytostanols and fatty acids. The employed approach complements the existing GC-based methods for the analysis of phytosteryl/phytostanyl esters in low-fat and fat-based products and thus creates a base for authenticity assessments of these types of novel foods.