基于纳米金与适配体的赭曲霉毒素A检测方法研究

以赭曲霉毒素A适配体作为识别分子荧光素发射的荧光作为检测信号、纳米金作为荧光信号淬灭剂,建立一种高灵敏度的赭曲霉毒素A荧光检测方法。结果表明:该检测体系检测限达到10nmol/L,在25~1 000nmol/L浓度范围具有线性关系,相关系数为0.991,具有较好的实用性。该荧光检测法同传统方法相比,提高了检测效率,为更好地进行赭曲霉毒素A检测控制提供了技术支持。     

基于染料Genefinder和适配体的荧光传感体系检测赭曲霉毒素A

构建基于核酸染料Genefinder和适配体的荧光传感体系用于检测赭曲霉毒素A（ochratoxin A，OTA）。OTA适配体与其互补链形成双链结构，Genefinder染料与双链结构DNA结合后产生较强的荧光信号，加入OTA后，适配体与OTA结合形成四链体结构，双链打开，Genefinder染料荧光强度降低。结果表明，该荧光传感体系的线性范围为50 pg/L～300 ng/L，实际检出限为50 pg/L，对OTA有较强的选择性。这种简单、快速、特异性强的荧光传感体系具有广泛的应用前景。     

基于靶标诱导滚环扩增的无标记适配体生物传感器快速检测赭曲霉毒素A

该文构建一种基于靶标诱导滚环扩增（rolling circle amplification,RCA）的无标记适配体快速检测赭曲霉毒素A（ochratoxin A,OTA）生物传感器。该生物传感器探针由RCA 引物与OTA 适配体两部分组成,在OTA 存在的环境中,OTA 适配体特异性识别靶标,探针结构被打开,RCA 引物与环状DNA 模板（circular DNA template,CT）结合开启RCA 反应,加入核酸染料SYBR Gold 产生荧光信号。此生物传感器具有较高的特异性,检测限为6.6×10-2 nmol/L,线性检测范围为6.6×10-2～660 nmol/L,可用于具体的分析检测。此生物传感器无需复杂化学修饰且操作简单,在食品安全检测中具有良好的应用前景。     

基于适配体荧光传感器检测山药和薏苡仁中的赭曲霉毒素A

目的 构建一种操作简单、选择性好、快速检测山药和薏苡仁中赭曲霉毒素A(ochratoxinA,OTA)的适配体荧光传感检测方法。方法 制备表面包裹适配体且孔穴负载荧光染料罗丹明6G的二氧化硅纳米颗粒,OTA与其表面的适配体结合后,检测溶液的荧光信号变化,从而实现OTA浓度的检测。结果 在最佳条件下, OTA的质量浓度在5～500 ng/mL范围内与荧光强度差值呈良好的线性关系,相关系数为0.9918,检出限为2.06ng/mL。应用于山药和薏苡仁中OTA的检测,加标回收率为90.7%～107.1%,相对标准偏差为2.41%～5.66%。结论 该方法操作简便、选择性好、稳定性高,有望用于药食同源中药材中OTA的快速检测。     

赭曲霉毒素A核酸适配体筛选

目的筛选小麦和其他相关食品中常见的赭曲霉毒素A真菌毒素核酸适配体。方法采用固态靶标筛选策略和磁分离的筛选方法筛选赭曲霉毒素A的核酸适配体。结果获得的赭曲霉毒素A核酸适配体亲和力较高,解离常数为纳摩尔级;特异性好,与赭曲霉毒素A结构相似性化合物如赭曲霉毒素B、N-乙酰苯丙氨酸或华法令不结合或结合力非常弱。结论本文采用固态靶标筛选策略和磁分离的SELEX筛选方法获得了赭曲霉毒素A的高特异性、高亲和力核酸适配体,有望在农产品质量安全领域替代传统抗体开发真菌毒素快速检测传感器或制备固相亲和柱。     

赭曲霉毒素A直接竞争ELISA试剂盒的研制

在多克隆抗体的基础上研制了赭曲霉毒素A(OTA)直接竞争酶联免疫检测(cd-ELISA)试剂盒.在0 ～ 10 ng/mL范围内,该试剂盒50％抑制率(IC50)为1.09 ng/mL,检测灵敏度(IC15)为0.08 ng/mL;与赭曲霉毒素B、C的交叉反应率分别为6.28％和0.16％,而与黄曲霉毒素B1等生物毒素未见有交叉反应;板内与板间平均变异系数分别为2.21％和2.79％;花生、玉米和玉米粉3种样品中OTA的检测低限分别为1.71,1.26和1.85 μg/kg,平均添加回收率在83.80％～ 91.40％;与HPLC检测方法具有较高的相关性,相关系数(R2)分别为0.94、0.88和0.90;检测时间只需20 min,可用于花生、玉米及玉米粉中OTA的批量快速筛查.     

基于核酸适配体-金纳米粒子比色传感器快速检测食品中赭曲霉毒素A

本研究以核酸适配体为识别元件实现对赭曲霉毒素A(OTA)的高选择性识别,以及采用金纳米粒子做为比色探针,建立了适用于OTA快速检测的比色适配体传感器。研究结果表明,该比色传感器对OTA具有较高的灵敏度和特异性,操作简单快速,能用于实际食品样品中OTA的快速筛查检测;该比色传感器在520nm和650nm下吸光度的比值(A520/A650)与OTA浓度在0.05~5μM的范围内呈线性相关,检测限为0.02μM。     

赭曲霉毒素A的适配体筛选

目 的 筛选小麦和其他相关食品中常见的赭曲霉毒素A真菌毒素核酸适配体。方 法 采用固态靶标筛选策略和磁分离的筛选方法筛选赭曲霉毒素A的核酸适配体。结 果 获得的赭曲霉毒素A核酸适配体亲和力较高,解离常数为纳摩尔级;特异性好,与赭曲霉毒素A结构相似性化合物如赭曲霉毒素B、N-乙酰苯丙氨酸或华法令不结合或结合力非常弱。结 论 本文采用固态靶标筛选策略和磁分离的SELEX筛选方法获得了赭曲霉毒素A的高特异性,高亲和力核酸适配体,有望在农产品质量安全领域替代传统抗体开发真菌毒素快速检测传感器或制备固相亲和柱。     

基于无标记金纳米簇的新型荧光生物传感器在赭曲霉毒素A快速检测中的应用

基于快速合成无标记核酸适配体（aptamer,Apt）模板金纳米簇（gold nanocluster,AuNCs）,并以核酸Apt部分互补的单链DNA修饰的金纳米颗粒（gold nanoparticles,AuNPs）结合,构建新型荧光复合纳米生物传感器。利用检测靶标与核酸Apt之间更强结合力,使已荧光猝灭的Apt-AuNCs@cDNA-AuNPs复合纳米传感器发生荧光共振能量转移,最终体系荧光强度值恢复的特性,用于快速准确检测赭曲霉毒素A（ochratoxin A,OTA）。结果表明,OTA质量浓度在0.01～2.5 ng/mL之间,荧光强度对应峰值（FI）与OTA质量浓度（C）呈现良好的线性关系,回归方程分别为FI=689.84lgC（OTA）＋8 315.31;检出限为0.025 ng/mL（信噪比为3）。该荧光生物传感器具有合成及操作简单、灵敏度高、选择性强、稳定性好及检测下限低的特点,预期在食品中相关有害因子的安全检测等提供一种新的思路和平台。     

磁控双色上转换荧光适配体传感器同时检测玉米和燕麦粉中的赭曲霉毒素A与玉米赤霉烯酮

目的 建立磁控双色上转换荧光法同时检测玉米和燕麦粉中赭曲霉毒素A(ochratoxin A,OTA)与玉米赤霉烯酮(zearalenone,ZEN)的含量。方法 利用溶剂热法合成了两种油酸封端的核壳型上转换纳米材料,通过表面改性法和戊二醛法制备了表面分别偶联OTA、ZEN适配体的核壳型上转换荧光探针。同时制备了表面原位生长四氧化三铁纳米颗粒的二硫化钼纳米片,作为淬灭剂。OTA、ZEN和适配体特异性结合后,通过磁分离后检测溶液的荧光强度值,从而实现OTA和ZEN的检测。结果 在最佳检测条件下,OTA与ZEN的质量浓度在0.05～500.00 ng/mL范围内与两种上转换荧光探针的荧光强度的对数值呈良好的线性关系,相关系数分别为0.9949和0.9972,对OTA的检出限为3.97×10^-2ng/mL,对ZEN的检出限为3.11×10^-2ng/mL,应用于玉米粉和燕麦粉中OTA和ZEN的检测,加标回收率为91.7%～109.4%。结论 该方法检测灵敏度较高,并具有较好的特异性,可用于玉米和燕麦粉中OTA和ZEN的高灵敏检测。     

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.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press