芝麻过敏原的分离、鉴定与纯化

通过SDS-PAGE电泳分离芝麻的蛋白质组份,采用免疫印迹(Westem-blotting方法其鉴定过敏原,通过离子交换层析对芝麻主要过敏原进行初步纯化.结果表明白芝麻粗提液SDS-PAGE显示有14条蛋白条带.黑芝麻粗提掖SDS-PAGE显示有16条蛋白条带.Western-Blotting显示对芝麻过敏患者的混合阳性血清均能与黑芝麻、白芝麻11 ku蛋白反应,离子交换层析可初步纯化出白芝麻11 ku的过敏原蛋白.     

间接竞争ELISA法检测坚果类过敏原特异性研究

以腰果蛋白为过敏抗原,腰果蛋白致敏的阳性小鼠血清作为一抗,羊抗鼠Ig E-HRP为二抗建立双抗体间接酶联免疫吸附实验（ELISA）体系,通过棋盘法确定腰果蛋白最佳反应条件工作浓度为15.92μg/m L,最佳一抗稀释度均为1∶400,最佳酶标二抗的稀释度为1∶1000,腰果蛋白浓度为1.99μg/m L。并用该方法分别对腰果、核桃、榛子、开心果、板栗、杏仁等六种坚果进行检测分析,未发现有交叉反应,本实验建立的间接竞争性ELISA诊断方法具有良好的敏感性和特异性,为坚果过敏性食品的监测及时而准确的诊断奠定了基础。      

白果过敏蛋白及其过敏原性研究

对白果的主要过敏蛋白进行鉴定,并对其过敏原性进行分析。以SDS-PAGE和Western-Blotting分析鉴定白果蛋白提取液中的蛋白质组分和过敏蛋白,通过间接ELISA法检测过敏小鼠血清中sIgE的效价。白果的蛋白质条带主要有13条,其中以21kD和32kD含量最多。Western-Blotting分析结果表明,白果蛋白中存在3条过敏原蛋白,分子质量分别为21、32、36kD。当酶标二抗稀释度为1:1000,白果蛋白包被质量浓度为50μg/mL,间接ELISA测得过敏小鼠血清中sIgE的效价为1:6400。对白果蛋白进行分析鉴定,明确了白果中存在的过敏原蛋白。     

物理法结合酶法脱除坚果类过敏原的技术研究

分别对4种坚果中的过敏蛋白进行分离提取,研究其蛋白特性,运用物理方法如高温、高压和微波超声波结合酶法作用于坚果过敏蛋白,探索脱除坚果类蛋白致敏性的最佳方法。结果表明:腰果、杏仁、核桃等坚果蛋白都使人产生过敏反应,经过高温、高压、超声波—微波联合萃取及蛋白酶处理后,均能使其致敏性明显降低。其中超声波—微波与酶法联合处理,超声波开启,作用温度90℃、时间240 s、微波功率700 W,0.25%胰蛋白酶处理5 min能完全脱除坚果类过敏原蛋白,是最佳脱敏方法。     

开心果过敏原的分离纯化及紫外光谱分析

目的 对开心果中的过敏蛋白进行分离纯化, 了解开心果过敏蛋白的初级结构和致敏性。方法 将不同加工处理的开心果用二氯甲烷、TBS缓冲液进行过敏蛋白的提取分离, 采用硫酸铵分级沉淀来初步提纯过敏蛋白, 再通过透析、离子交换柱层析手段对开心果的致敏蛋白进一步纯化, 最后通过考马斯亮蓝测蛋白含量, 用紫外分光光度计波峰表征, 确定开心果致敏蛋白质种类, 通过SDS-PAGE电泳分析和WB免疫印迹实验验证开心果分离蛋白的致敏性。结果 不同比例的有机溶剂提取开心果蛋白的分离效果不同, 原味开心果1:3的得率最高达到49.49%; 不同饱和度的硫酸铵沉淀蛋白质不同, 浓度越小, 析出蛋白质种类越多; 经离子交换层析柱分离纯化之后, 蛋白质的种类组分稳定, 结合之外扫描图谱分析所测物质的结构中含有双键或三键, 属于复合蛋白质的结构。结论 开心果过敏原属于蛋白复合结构, 主要以双键和三键的形式存在, 热处理和盐焗加工会降低开心果过敏原的致敏性。     

腰果过敏研究进展

腰果过敏是一种严重的树坚果过敏。近年来,随着腰果消费量迅速增长,腰果过敏发生率随之呈上升趋势,腰果正在成为一种重要的食物过敏原。少量的过敏原可导致严重的过敏反应,甚至危及性命。然而,目前腰果过敏显然是一个被严重低估的健康问题,尤其是对儿童。因此,社会迫切需要给予腰果过敏足够的重视,并有必要向公众广泛宣传腰果过敏的严重性。本文就腰果过敏的流行病学、过敏原成分、临床特点、诊断以及预防治疗等方面进行系统综述,旨在为腰果过敏的社会认识和深入研究提供科学信息。     

牛奶过敏原的分离、鉴定与纯化

对牛奶过敏原进行分离、鉴定与纯化。通过SDS-PAGE电泳分离牛奶的蛋白质组份,采用免疫印迹(Western-blotting)方法鉴定过敏原,通过离子交换层析对牛奶过敏原进行初步纯化。结果表明,鲜牛奶粗提液SDS-PAGE显示蛋白条带有12条,奶粉粗提液SDS-PAGE显示出的蛋白条带与鲜牛奶的蛋白条带基本一致。鲜牛奶Western-Blotting显示14ku的阳性条带。离子交换层析可初步纯化出14ku的过敏原蛋白。本研究对牛奶过敏原进行了分离和鉴定,并初步纯化出牛奶的主要过敏原。     

澳洲坚果蛋白夹心ELISA方法的建立及应用

利用碱溶酸沉法提取未加工的澳洲坚果蛋白,分别制备鼠、兔多克隆抗体,并以兔多抗为捕获抗体,鼠多抗为检测抗体建立了双抗夹心酶联免疫检测方法。该方法的检出限为(0.95±0.17)ng/mL。方法与大豆、核桃、榛果、杏仁、花生、开心果、腰果和小麦蛋白无明显交叉反应,证明该方法特异性良好。焙烤的澳洲坚果和焙烤饼干中澳洲坚果蛋白的添加回收率为73.67%～77.03%,说明该方法不仅适用于未加工澳洲坚果蛋白的准确检测,也适用于热加工后以及焙烤食品中澳洲坚果蛋白的定量检测。     

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。     

小麦食源性过敏原致敏亚基分析

通过SDS-PAGE对小麦亚基成分分析,采用ImmunoCAP 250全自动体外免疫检测系统测定小麦过敏患者不同个体对小麦致敏蛋白的识别结果,并以我国12例小麦过敏患者的血清为探针,3例正常人的血清池为对照,与师栾02-1小麦粉进行还原态一维电泳免疫印迹分析,鉴定引起我国小麦过敏人群过敏的小麦过敏原及其致敏概率。结果表明,小麦过敏原蛋白亚基的致敏概率自高至低的顺序依次为17 ku(6/12)、28ku(6/12)、14ku(5/12)、19ku(5/12)、22ku(5/12)、24ku(5/12)、25 ku(5/12)、26ku(5/12)、11 ku(4/12)、12ku(4/12)、16 ku(4/12)、21 ku(4/12)、27 ku(4/12)、18 ku(3/12)、30 ku(3/12)、31 ku(3/12)、36ku(3/12)、47ku(3/12)、83ku(3/12),其他一些蛋白亚基致敏概率为1/6或1/12。     

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