免疫亲和柱净化-HPLC柱后光化学衍生荧光法测定花生饮料中的黄曲霉毒素B_1

建立了免疫亲和柱净化-光化学衍生高效液相色谱荧光法测定花生饮料中黄曲霉毒素B1含量的方法。试样经乙腈-水溶液(体积比80∶20)提取,免疫亲和柱富集和净化后,采用Thermo Syncronis C_(18)色谱柱(250mm×4.6mm,5μm),以甲醇-水(体积比55∶45)为流动相,等度洗脱,荧光检测器检测(Ex:360nm,Em:440nm)。结果表明:黄曲霉毒素B1检出限为7.54×10~(-3)μg/kg;标准曲线的线性范围为0.1～20.0ng/mL(r=0.9999);3个不同水平的加标平均回收率为96.88%～98.82%,RSD值为0.85%～1.07%。10批试样中黄曲霉毒素B_1测定值为0～2.09μg/kg,均无过量残留。该方法具有操作简便、灵敏度高、重现性佳等特点,适用于花生饮料中黄曲霉毒素B_1的检测。     

免疫亲和柱净化-UPLC-MS/MS测定花生中黄曲霉毒素B_1

为提高花生中黄曲霉毒素B_1的检测效率和准确性,试验通过对提取溶剂、色谱条件和质谱条件的优化,建立了免疫亲和柱-超高效液相色谱串联质谱(UPLC-MS/MS)快速测定花生中黄曲霉毒素B_1的方法,并对方法进行了评估。结果表明,用甲醇-水(60∶40,V/V)对样品进行提取,采用黄曲霉毒素免疫亲和柱萃取、净化,以0.1%甲酸水溶液、0.1%甲酸乙腈溶液作为超高效液相色谱的流动相,在电喷雾离子源(ESI)正离子模式下采用多反应监测(MRM)对花生中黄曲霉毒素B_1进行定性、定量检测,在5.5 min内完成一个样品的分析。结果表明,黄曲霉毒素B_1在0.1~56.0 ng/m L的线性定量范围,相关系数高达0.999 42,检出限低至0.02μg/kg,定量限精确至0.1μg/kg,低、中、高浓度回收率为82%~92%,相对标准偏差5%。该方法具有前处理简单、净化效果好和准确度高的优点,适用于花生等复杂基质样品的黄曲霉毒素B_1定性和定量检测。     

高效液相色谱-光化学柱后衍生法测定紫苏籽中黄曲霉毒素B1

目的建立一种高效液相色谱-光化学柱后衍生法测定紫苏籽中黄曲霉毒素B_1的检测方法。方法样品经乙腈-水溶液(84:16,V:V)提取,用免疫亲和柱净化后,经光化学衍生器衍生,在高效液相色谱仪荧光检测器上检测。结果该方法对黄曲霉毒素B_1的最低检测限为0.05μg/kg,定量限为0.20μg/kg,相关系数为0.9990,加标回收率为86.0%～93.5%,相对标准偏差(relative standard deviation, RSD)为1.94%。结论该方法快速、准确、灵敏,适合测定紫苏籽中黄曲霉毒素B_1的含量。     

酶联免疫法检测混合植物油中黄曲霉毒素B1的含量

目的建立酶联免疫法测定混合植物油中黄曲霉毒素B_1含量的分析方法。方法采用直接竞争酶联免疫吸附法对样品进行测定。样品经甲醇溶液提取,提取的抗原及黄曲霉毒素B_1标记物与微孔板上的黄曲霉毒素B_1特异性单克隆抗体竞争结合,洗涤除去未结合杂质。将底物加入孵育,产生蓝色产物,加入终止液终止反应蓝色产物变成黄色产物,450nm处测量吸光度。结果本方法在2h内完成混合植物油中黄曲霉毒素B_1含量的测定。黄曲霉毒素B_1的加标浓度在1.0～20.0μg/kg之间时的回收率为76.5%～120.2%,方法定量限为1.00μg/kg。结论该方法快速、准确、灵敏,适合测定混合植物油中黄曲霉毒素B_1。     

酶联免疫法检测混合植物油中黄曲霉毒素B_1含量

目的建立酶联免疫法测定混合植物油中黄曲霉毒素B_1含量的分析方法。方法采用直接竞争酶联免疫吸附法对样品进行测定。样品经甲醇溶液提取,提取的抗原及黄曲霉毒素B_1标记物与微孔板上的黄曲霉毒素B_1特异性单克隆抗体竞争结合,洗涤除去未结合杂质。将底物加入孵育,产生蓝色产物,加入终止液终止反应蓝色产物变成黄色产物,450nm处测量吸光度。结果本方法在2h内完成混合植物油中黄曲霉毒素B_1含量的测定。黄曲霉毒素B_1的加标浓度在1.0～20.0μg/kg之间时的回收率为76.5%～120.2%,方法定量限为1.00μg/kg。结论该方法快速、准确、灵敏,适合测定混合植物油中黄曲霉毒素B_1。     

免疫亲和柱净化-高效液相色谱柱后光化学衍生- 荧光检测器检测食品中黄曲霉毒素

目的建立一种免疫亲和固相萃取柱净化-高效液相色谱柱后光化学衍生-荧光检测器同时测定食品中黄曲霉毒素B_1、B_2、G_1和G_2的方法。方法以甲醇-水(70:30,V:V)为提取溶剂,采用高速均质提取,并经过黄曲霉毒素免疫亲和柱净化。结果经月旭公司Welch Ultimate~XB-C_(18)色谱柱(250 mm×4.6 mm,5μm)分离后使用光化学衍生器进行柱后衍生,并采用带荧光检测器的高效液相色谱仪检测,流动相为甲醇/水(45:55,V:V)。黄曲霉毒素B_1、B_2、G_1和G_2线性范围在0.3~50.0μg/L之间,线性相关系数均大于0.999,B_1、B_2、G_1和G_2检出限分别为0.15μg/kg、0.05μg/kg、0.15μg/kg、0.05μg/kg。在3个加标浓度下大米、花生和瓜子等试样的回收率在80.7%~92.6%之间;相对标准偏差(RSD)在2.04~3.87%之间。结论该方法的灵敏度、准确度和精密度均符合黄曲霉毒素的检测技术要求,且简便快速,适用于食品中黄曲霉毒素B_1,B_2,G_1和G_2的准确测定。     

光化学衍生-高效液相色谱法测定大米中黄曲霉毒素B_1含量

建立了一种测定大米中黄曲霉毒素B_1含量的光化学衍生-高效液相色谱方法:试样经乙腈与水的混合液(体积比84:16)提取,多功能净化柱净化、浓缩、高效液相色谱分离,在线光化学柱后衍生,荧光检测器检测,外标法定量,在优化的条件下,黄曲霉毒素B_1的浓度分别为1.0~40.0μg/L时,浓度与峰面积线性关系良好,相关系数0.9996;加标浓度为5~10μg/kg,样品回收率为80.9%~98.7%,平行相对偏差为3.87%,该方法简单快速、灵敏度高、重现性好,用于大米中黄曲霉毒素B_1的测定,效果更好。     

高效液相色谱-串联质谱法快速检测粮油制品中黄曲霉毒素B1的含量

目的建立高效液相色谱-串联质谱法快速测定粮油制品中黄曲霉毒素B_1含量的分析方法。方法样品中的黄曲霉毒素B_1经提取、免疫亲和柱净化、浓缩等步骤,以5 mmol/L乙酸铵溶液、乙腈-甲醇溶液(50:50,V:V)为流动相,按照梯度洗脱程序,通过液相色谱-串联质谱法进行测定,外标法定量。结果黄曲霉毒素B_1在0.2～20ng/mL浓度范围内与峰面积呈现良好的线性关系,线性方程为Y=68577.3X-20845,r0.998,加标回收率在85.0%～94.1%之间,相对标准偏差(relative standard deviation, RSD)5.5%,方法检出限和定量限分别为0.07和0.2μg/kg。结论该方法测定结果准确、可靠,可用于快速测定粮油制品中黄曲霉毒素B_1的含量。     

甜面酱中黄曲霉毒素B_1、B_2检测方法的研究

建立了用液相色谱测定甜面酱中黄曲霉毒素B_1、B_2含量的方法。试验采用C18色谱柱,以水-甲醇(55+45)为流动相,柱温25℃,荧光检测器检测。该方法黄曲霉毒素B_1、B_2检出限0.8μg/kg(进样量为50μL,S/N=30),标准曲线的线性范围分别为5~200μg/L(r=0.999 4,0.999 2)。该方法测定甜面酱中的黄曲霉毒素B_1、B_2,样品加标回收率(3份25.0 g样品,每份加标1,2和4μg)94.0%~98.3%、93.8%~99.4%,相对标准偏差RSD(n=10)0.78%、1.13%。     

酶联免疫法检测酱油中的黄曲霉毒素B1

目的建立酶联免疫法检测酱油中黄曲霉毒素B_1(Aflatoxin B_1,AFB_1)的分析方法。方法酱油样本经纯乙腈(料液比=1:2,V:V)提取,再做1:9稀释,通过酶联免疫吸附法(enzyme linked immunosorbent assay,ELISA)测定样本中AFB_1。结果当加标浓度为2μg/kg和5μg/kg时,纯乙腈对酱油中AFB_1的提取回收率结果分别为121.3%和106.5%;方法检出限为1μg/kg。与国标方法检测结果的相对标准偏差小于10%。结论本方法准确、灵敏度高,可适用于酱油中AFB_1的检测。     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.