间接竞争ELISA法检测谷物中T-2毒素

T-2毒素是单端孢霉烯族毒素的重要代表,在单端孢霉烯族毒素中毒性最强,是主要的食品污染源之一,用间接竞争酶联免疫分析法(ELISA)对谷物中的T-2毒素进行了测定。从样品的处理、T-2毒素的添加回收及ELISA的实验检测等方面进行试验,最终结果用分析软件分析相关数据得到相关系数为0.998,IC50为1.3μg/kg,标准品浓度为0~16.2μg/kg,灵敏度为0.2μg/kg,添加回收率均大于90%。该法测定T-2毒素方法简便,特异性高,灵敏度高,重复性好,适合用于检测谷物中的T-2毒素。     

免疫亲和柱-高效液相色谱法同时检测谷物中T-2毒素和HT-2毒素含量

建立了免疫亲和柱净化-柱前化学衍生-高效液相色谱荧光检测器同时检测谷物中T-2毒素和HT-2毒素的方法。样品经溶剂[V(甲醇)∶V(水)=80∶20]提取,通过免疫亲和柱净化(IAC),以氰酸蒽(1-AN)为衍生化试剂、4-二甲基氨基吡啶(DMAP)为催化剂进行衍生,以ZORBAX Eclipse XDB苯基柱为分离柱,乙腈-水为流动相进行高效液相色谱分离和检测。在0.005⁰.5μg/g内呈良好线性,检出限为0.005μg/g,添加回收率为82.0%0.5μg/g内呈良好线性,检出限为0.005μg/g,添加回收率为82.0%¹08.0%,RSD<15.5%。     

呕吐毒素时间分辨荧光免疫层析法的建立与评价

构建并评价了呕吐毒素(Deoxynivalenol,DON)时间分辨荧光免疫层析法(TRFIA)。以Eu3+螯合物的纳米微球为荧光探针标记抗DON单抗,采用竞争抑制建立免疫层析定量方法,优化了微球与抗体标记量,检测的环境温度、反应时间、加样体积及缓冲体系;研究了方法的灵敏度、精密度及准确度。结果表明,每100 μL荧光微球结合纯单抗50 μg,最佳划膜浓度为1.0 mg/mL,最佳测定条件为室温(25±2)℃,10 min,加样体积100 μL,PBS (0.01 mol/L,pH7.2)的缓冲体系,方法的灵敏度为0.25 ng/mL,线性范围为0.5~25.0 ng/mL,玉米、小麦阴性样本(加标浓度200、500、1000、2000 μg/kg)平均加标回收率为91.4%~109.3%,6种典型样本经TRFIA与免疫亲和净化-高效液相色谱法(IAC-HPLC)同时测定DON含量,相关系数r达0.9754。TRFIA具有灵敏度高、速度快、定量准等技术特点,适用于谷物及制品中DON的快速定量。     

恩诺沙星时间分辨荧光免疫分析方法的建立

目的：采用时间分辨荧光免疫分析(time-resolved fluoroimmunoassay,TRFIA)技术建立高灵敏的恩诺沙星(enrofloxacin,ENR)快速检测方法。方法：以包被抗原(ENR-OVA)包被微孔板,与游离的恩诺沙星共同竞争抗恩诺沙星抗体,以铕(Eu3+)标记的羊抗兔抗体进行示踪。结果：方法的批内变异系数小于10%、批间变异系数小于15%,平均回收率为91.62%,灵敏度为5ng/L,可测范围为0.01～100μg/L,ED20、ED50和ED80分别为0.088、3.40μg/L和32.81μg/L。结论：ENR-TRFIA方法稳定性好、可测范围宽,具有很好的应用前景。     

T-2毒素胶体金免疫层析快速检测试纸条的研制

应用胶体金免疫层析技术,研制出一种快速检测T-2毒素的方法。采用柠檬酸三钠还原法制备20 nm胶体金,标记抗T-2毒素多克隆抗体并喷于玻璃纤维上,T-2毒素偶联抗原和羊抗兔二抗分别结合于硝酸纤维素膜上,经过试纸条层析条件优化,依次将样本垫、金标结合释放垫、硝酸纤维膜和吸水纸组装切割成胶体金试纸条。测试结果表明T-2毒素快速检测试纸条的灵敏度为50μg/L,检测时间为10 min,批内和批间重复性好,保存期为3个月。使用简单方便,非常适合现场快速检测T-2毒素。     

高效液相色谱-串联质谱法测定3种水产品中的T-2毒素与HT-2毒素

建立高效液相色谱-串联质谱定量快速检测罗非鱼、南美白对虾和黄金贝中的T-2毒素与HT-2毒素方法。以10 mL乙酸乙酯作为提取溶剂,振荡提取,无水硫酸钠除水,定量移取5 mL提取液氮气吹干后用1 mL含有0.1%甲酸的甲醇-5 mmol/L乙酸铵溶液（3∶7,V/V）复溶,正己烷脱脂净化,基质匹配法外标定量。3 种水产品中T-2毒素和HT-2毒素的检出限分别为2 μg/kg和4 μg/kg。T-2毒素质量浓度为2～100 ng/mL,HT-2毒素质量浓度为4～200 ng/mL,范围内线性良好。在3 种样本中进行3 个水平添加实验（n=6）,T-2毒素回收率为84.3%～109.9%,HT-2毒素的回收率为90.9%～103.2%。T-2毒素的相对标准偏差为2.0%～8.7%,HT-2毒素的相对标准偏差为2.6%～10.6%。本方法简便快速、准确度好、精密度高,适用于3 种代表性水产品中T-2与HT-2毒素的同时检测。     

脱氧雪腐镰刀菌烯醇(DON)直接竞争ELISA方法的建立

利用前期制备得到的DON酶标抗原(辣根过氧化物酶标记)以及抗DON抗体,建立检测食品中DON含量的直接竞争ELISA方法。该方法的检测范围1～100ng/mL,灵敏度达0.56ng/mL,半数抑制浓度IC50为10ng/mL;与DON类似物T-2毒素的交叉反应率为12%;玉米淀粉样品回收率在80.2%～91.1%之间,平均批间变异<15%,平均批内变异<3%。     

基于毒性效应通路荧光细胞传感模型的T-2毒素毒性筛查

为实现T-2毒素的可视化毒性筛查,利用T-2毒素毒性通路中AP-1的关键靶点应答元件TRE与红色荧光蛋白（mCherry）的启动子构建pcDNA3.1-TRE-mCherry荧光质粒,建立荧光HEK293细胞传感筛查模型;同时,为验证该细胞传感模型的适用性,对实际样品中残留的T-2毒素和T-2毒素的主要代谢产物HT-2毒素进行了毒性监测。结果表明,T-2毒素刺激模式细胞8 h时,细胞内的红色荧光强度达到最高值并趋于稳定。当T-2毒素质量浓度在1~25 ng/mL时,其与荧光强度呈线性相关,线性方程为y=1.149 38x+64.72,R²=0.969。根据剂量曲线得出T-2毒素的EC₅₀为16.27 ng/mL,检测限为0.691 ng/mL。该细胞传感模型用于样品加标实验,平均加标回收率为86.13%~126.20%,对HT-2毒素进行毒性筛查得到EC₅₀为27.65 ng/mL。     

T-2毒素快速定量检测试纸条的研究

为研制一种快速定量检测玉米中T-2毒素含量的胶体金试纸条,对T-2毒素单克隆抗体进行标记并对胶体金试纸条性能进行研究。用胶体金标记T-2毒素单克隆抗体,通过测定加入不同量碳酸钾后吸光度值的变化,确定标记的最佳pH值,通过与抗原进行正交试验确定最佳组合条件,应用胶体金定量读数仪通过检测线和对照线的对比,检测试纸条的性能。结果表明,单克隆抗体标记的最佳pH值为8.5,最佳标记浓度为20μg/mL,抗原的包被浓度为0.5mg/mL,羊抗鼠IgG的包被浓度为1.0mg/mL,试纸条检测T-2毒素标准品的检测限为5μg/kg。T-2毒素胶体金快速定量检测试纸条检测方法可得出具体数据,与常见真菌毒素无交叉反应,回收率在77%~117.6%之间,批内和批间重复性检测变异系数小于10%,玉米中T-2毒素的检测结果与高效液相法检测结果一致。T-2毒素胶体金快速定量检测试纸条可用于玉米中T-2毒素含量的快速定量检测。     

超高效液相色谱检测奶及奶制品中的 M族黄曲霉毒素

摘 要：目的 建立一种免疫亲和柱净化-超高效液相色谱法同时测定奶及奶制品中M族黄曲霉毒素的方法。方法 以乙腈为提取剂和蛋白沉淀剂,采用涡旋混合及超声提取,免疫亲和柱净化。结果 经Welch Ultimate XB-C18（100 mm×2.1 mm,1.8 μm）色谱柱分离,应用大体积流通池荧光检测,流动相为水和乙腈/甲醇(1:1)。线性范围在0.01~5.00 ng/mL之间,线性系数均大于0.999,黄曲霉毒素M1、M2的检出限为0.003 μg/kg。免疫亲和柱对黄曲霉毒素M1、M2的回收率均在80%以上,液态奶中添加0.05、0.2、1.0 μg/kg的回收率在85.6%~106.4%之间,奶粉中添加0.5、2.0、10.0 μg/kg的回收率在81.5%~93.4%之间。结论 该方法可以适用于奶粉、液态奶中M族黄曲霉毒素检测。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

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.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.