气相色谱法测定蛋和蛋制品中的六六六、滴滴涕

建立了蛋和蛋制品中六六六、滴滴涕残留量的气相色谱检测方法.样品经正己烷提取、浓硫酸净化,气相色谱分离后,电子捕获检测器检测,外标法定量.在5 μg/kg～20 μg/kg添加水平,回收率在75.4%～90.3%之间,变异系数在2.5%～9.1%之间.以S/N=3计算,方法最低检出限为5.0 μg/kg.结果表明,该法简便、灵敏、准确,适用于鸡蛋中的六六六、滴滴涕残留量的分析.     

超高效液相色谱-串联质谱法快速测定动物源食品中万古霉素残留量

提供一种利用超高效液相色谱-串联质谱（ultra-high performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS）法快速测定动物源性食品中万古霉素残留量的方法。冻猪背膘、冻猪去骨前腿皮和 冻猪去骨前腿肉样品用0.1%甲酸水溶液-乙腈溶液（90∶10,V/V）提取,所得提取液用水饱和正己烷除脂、MCX 固相萃取柱净化,净化液经氮吹浓缩、流动相定容后用UPLC-MS/MS仪测定。结果表明：在2.0～100.0 μg/L质 量浓度范围内,万古霉素的线性关系良好,R2＞0.999 9;该方法的最低检出限为0.3 μg/kg,定量限为1.0 μg/kg; 在10.0、20.0、50.0、100.0 μg/kg 4 个添加水平下,3 种样品中万古霉素的回收率为70.05%～102.97%,相对标准偏 差≤4.65%。该方法有效解决了样品基质效应大、灵敏度低等问题,能够保证分析结果的准确性,适用于动物源性 食品,尤其是高脂肪含量的动物源性食品中万古霉素的残留量测定。     

液相色谱-串联质谱法检测牛奶中10种β-兴奋剂

建立了液相色谱-串联质谱同时检测牛奶中10种β-兴奋剂残留量的方法.样品经沉淀蛋白质,酸性水溶液提取, 提取液经Oasis MCX 固相萃取柱净化,LC/MS/MS方法测定.采用了Thermo Hypersil Gold (150×2.1 mm,5 μm) 色谱柱;5 mmol 乙酸铵水溶液-甲醇流动相,梯度洗脱.方法线性相关系数r均大于0.999.克伦特罗检出限为1.68 μg/kg,其余9种β-兴奋剂的检出限在0.146～0.203 μg/kg之间;克伦特罗定量限为3.37 μg/kg,其余9种β-兴奋剂的定量限在0.290～0.407 μg/kg之间.3个添加水平下,10种β-兴奋剂平均回收率在91% ～127%之间.     

液相色谱-串联质谱法检测蜂蜜中氟苯尼考及其代谢物残留量

目的 建立液相色谱-串联质谱法检测蜂蜜中氟苯尼考及其代谢物残留量的分析方法。方法 样品经氨化乙酸乙酯提取,通过DPC-2固相萃取柱净化,采用Poroshell 120 EC-C18柱分离,以10 mmol/L乙酸铵溶液-乙腈为流动相进行梯度洗脱,电喷雾正/负离子切换,多反应监测模式检测,同位素内标法定量。结果 氟苯尼考在0.2～30 μg/L时具有良好的线性关系,相关系数大于0.999,检出限为0.05 μg/kg,回收率为85.5%~116.3%,相对标准偏差小于10%。氟苯尼考胺在1～30 μg/L时具有良好的线性关系,相关系数大于0.999,检出限为0.3 μg/kg,回收率为85.6%~113.5%,相对标准偏差小于10%。结论 该方法快速、准确、灵敏, 适用于蜂蜜中氟苯尼考及其代谢物残留量的测定。     

固相萃取-高效液相色谱法测定食品中痕量花粉红染料

本实验建立了测定食品中痕量花粉红色素的高效液相色谱方法.样品经正己烷等溶液提取,经过中性氧化铝柱净化,以甲醇和水溶液为流动相进行色谱分离,在激发波长550 nm,发射波长580 nm的荧光条件下检测.花粉红的浓度在0.5～10.0 μg/ L 范围内与其色谱峰面积的线性关系良好( r=0.999),在1、5、10 μg/kg添加水平时的回收率为56.3 %～80.1%,RSD为2.8 %～5.7%.方法的定量检出限为1.0 μg/kg.     

高效液相色谱-串联质谱法同时测定畜禽肉和牛奶中地塞米松和氯丙嗪残留

目的 建立了高效液相色谱-串联质谱法同时测定畜禽肉和牛奶中地塞米松和氯丙嗪的残留量方法。方法 样品经乙腈提取,C18固相分散萃取净化,以0.1 %甲酸水溶液和乙腈为流动相进行梯度洗脱,经C18色谱柱分离,采用电喷雾正离子电离进行多反应监测模式监测,外标法定量。结果 该方法在0.5～200 μg/L浓度范围内与其呈良好的线性关系（r＞0.999）,方法检出限为0.1 μg/kg,定量限为0.3 μg/kg。在添加水平为0.5、1、5、10、25、50 μg/kg时,平均回收率为70.1~119.4%,相对标准偏差（RSD）为1.6～8.9%（n=6）。结论 该方法分析简单高效,灵敏度高,重复性好,定性定量准确,适用于畜禽肉和牛奶中地塞米松和氯丙嗪残留量的同时测定。     

毛细管色谱法检测小麦中溴甲烷残留量研究

探讨了用毛细管色谱法测定小麦中溴甲烷残留量的检测方法。以正己烷为溶剂,采用酸回流方法提取小麦中的溴甲烷,进行毛细管色谱分离,用ECD检测器检测。在0~47μg/mL范围内,色谱峰面积与浓度有较好的线性关系,线性方程y=90 484.89x,标准工作曲线相关系数R2为0.999 7,检出限为0.02 mg/kg。添加回收率为71.4%~86.77%。结果表明:采用酸回流方法提取,用毛细管色谱法检测操作简便、结果准确、灵敏度高,适合小麦中溴甲烷残留量的分析。     

气相色谱-负化学源电离-质谱法测定蔬菜中氟虫腈及其代谢物残留

建立气相色谱-负化学源电离-质谱法测定蔬菜中氟虫腈及其3 种代谢物氟甲腈、氟虫腈砜和氟虫腈亚砜残留量的方法。样品以乙腈提取,QuEChERS方法净化,采用基质校正曲线外标法定量。结果表明,氟虫腈及其代谢物在0.2～10.0 μg/L质量浓度范围内呈良好的线性关系;在1.0、5.0 μg/kg和10.0 μg/kg 3 个添加水平下,氟虫腈及其3 种代谢物的回收率在88.9%～105.8%之间,相对标准偏差在2.2%～7.6%之间;方法的检出限在0.2～0.3 μg/kg之间,定量限为1.0 μg/kg。该方法快速、简便、灵敏、准确,适用于蔬菜中氟虫腈及其代谢物残留的检测。     

同位素稀释-超高效液相色谱-串联质谱法测定水产品中孔雀石绿、结晶紫及其代谢物残留量的不确定度评定

建立同位素稀释-超高效液相色谱-串联质谱法同时测定水产品中孔雀石绿、结晶紫、隐性孔雀石绿、隐性结晶紫残留的不确定度评定方法,依据GB/T 19857-2005《水产品中孔雀石绿和结晶紫残留量的测定》,建立数学模型,通过不确定度来源分析建立不确定度评价方法。结果表明:标准溶液的配制和标准曲线拟合引入的不确定度最大,而同位素稀释法可以减小前处理过程和基质效应引入的不确定度。水产品中孔雀石绿残留量为14.26 μg/kg时,其扩展不确定度为1.35 μg/kg(k=2);结晶紫残留量为15.28 μg/kg时,其扩展不确定度为1.29 μg/kg(k=2);隐性孔雀石绿残留量为14.47 μg/kg时,其扩展不确定度为1.21 μg/kg(k=2);隐性结晶紫残留量为14.69 μg/kg时,其扩展不确定度为1.24 μg/kg(k=2)。     

高效液相色谱-荧光法测定食用油中 苯并（a）芘残留量

建立了高效液相色谱-荧光法测定食用油中苯并（a）芘残留量的方法。样品经正己烷提取、苯并（a）芘分子印迹柱净化后,进高效液相色谱仪,在RP-C18保护柱Welch C18 色谱柱（250 mm×4.6 mm×5 μm）、88%乙腈-水溶液为流动相、进样量10 μL条件下,用荧光检测器（激发波长384 nm,发射波长406 nm）测定食用油中苯并（a）芘含量。结果表明：该方法的苯并（a）芘线性范围为1～10 ng/mL,相关系数为0.999 91,检出限为0.2 μg/kg,平均加标回收率为94.9%。采用该方法对7种市售食用油中苯并（a）芘进行测定,结果发现,玉米胚芽油、鱼油中未检出苯并（a）芘,黑芝麻油中苯并（a）芘含量为2.780 μg/kg,胡麻籽油中苯并（a）芘含量为0.863 μg/kg,葵花仁油中苯并（a）芘含量为0.238 μg/kg,大蒜油中苯并（a）芘含量为0.410 μg/kg,五味子油中苯并（a）芘含量为0.132 μg/kg,均低于国家规定限量（10 μg/kg）。与国标法相比,该方法操作简便,节约时间,且灵敏度高、回收率稳定,适用于多种食用油中苯并（a）芘残留量的快速检测分析。     

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.     

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.     

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.     

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.