HPLC法与三氯化铁-盐酸法检测生鲜牛乳中甲醛掺假

采用高效液相色谱定量、三氯化铁-盐酸定性检测方法分别对生鲜乳中的甲醛质量分数进行对比实验研究.高效液相色谱检测方法中,以煮沸的纯净水提取样品中的甲醛,2,4-二硝基苯肼衍生,色谱柱为Agilent SB.C18,流动相为乙腈-水(65+35).测定波长为365 nm,外标定量方法回收率在87%以上.三氯化铁-盐酸定性检测方法甲醛掺假阳性样品显紫色.甲醛掺假定性检出限为5 mg/kg.三氯化铁-盐酸定性检测方法快速、灵敏、便捷,掺假现象容易判断,可以用于乳制品企业中推广.     

鸭血豆腐中甲醛测定超声前处理方法优化

采用响应面法(Response surface methology)优化超声波提取鸭血豆腐掺假甲醛的条件。在单因素试验的基础上,选取超声温度、超声时间、超声功率为影响因子,应用Box-Behnken中心组合设计建立数学模型,以回收率为响应值行分析。确定了最佳条件为:超声温度50℃、时间45 min、功率720 W。模型预测值为72.29%,验证值为71.23%,与预测值的相对误差为1.48%。超声提取鸭血豆腐中掺假的甲醛,结果表明具有简单快速、回收率高的优点,适用于鸭血豆腐中甲醛的提取测定。     

酱油掺假的鉴别检验

酱油掺假的鉴别检验杜连起（河北农业技术师范学院昌黎０６６６００）酱油是以蛋白质及淀粉为原料通过微生物发酵而生产的一种营养丰富的发酵调味品，因其能增强食欲、促进消化，所以，在日常生活中深受人们的欢迎。但在最近几年销售的酱油中出现了掺假的问题，即以次充优...     

IEF快速鉴别牛乳中掺入豆蛋白的方法

ＩＥＦ快速鉴别牛乳中掺入豆蛋白的方法杨锋，柳琪，滕葳，黎秀卿山东省农业科学院中心实验室２５０１００牛淑珍，林秋萍河南省农业科学院实验中心近年向牛乳及乳粉中掺假的现象时有发生。据卫生部门调查表明，乳与乳制品中掺假物质种类繁多，掺假物质达几十种。虽然掺假...     

慎待家具的游离甲醛问题

经销与使用家具，甚至生产家具都有一项应知应会的知识至关重要——游离甲醛问题。甲醛与游离甲醛是两个概念，须弄清楚后方可从容对待。 甲醛（ＣＨ２Ｏ），是一种化学物质。在人们日常生活的环境温度下为气体，虽无颜色但有强烈刺激性；通常情况下将甲醛在水中保存，形成甲醛水溶液，即福尔马林。甲醛的因、液、气三态均有不断的挥发性，即游离甲醛。游离甲醛在常温下每时每刻都在从发生源处外逸着。甲醛是目前家具主要用材原料——人造板的主要原料之一。甲醛与尿素经缩合反应后，生成脲醛树酯，人造板材则以脲醛树酯做为生产人造板的粘…     

啤酒中的甲醛

我们对啤酒酿造过程的甲醛含量变化做了跟踪检测，现与大家共同探讨。 1甲醛检测方法 目前啤酒中微量甲醛的检测方法有两种：一种是农业部颁发的绿色食品中甲醛的检测方法，标准号为NY／T273-2002；另一个是发酵酒卫生标准规定的分析方法，即国标法。另外可采用高效液相色谱进行检测，但目前此方法还未列入国家标准中。我们分析采用的是国标法，其原理是甲醛在过量乙酸铵的存在下与乙酰丙酮和氨离子生成黄色的3．5．二乙酰基．1．4．二氢吡啶化合物，在波长415nm处有最大吸收，颜色的深浅与甲醛含量成正比，相应可得出试样中甲醛的含量。     

基于原位电离-高分辨质谱技术结合特征脂肪酸含量鉴别菜籽油掺假的研究

建立了1种原位电离-高分辨质谱技术快速鉴定菜籽油是否掺假及气相色谱测定特征脂肪酸预测掺假比例的方法。通过收集不同品种油样和建立模型，建立实时鉴别菜籽油是否掺假大豆油、棉籽油或棕榈油的检测方法，并通过测定掺假菜籽油的特征脂肪酸，进一步确定掺假油品种及预测掺假比例。结果表明：原位电离技术鉴别纯品或掺假菜籽油准确度分别为89.1%和100%。根据棕榈酸、亚油酸、油酸等特征脂肪酸含量可准确定性掺假油品种，掺假大豆油、棉籽油和棕榈油的比例预测偏差分别为0～33%、2%～18%和4%～11%。     

蛋白质组学技术在不同物种乳掺假检测中的应用

乳品是人类重要的营养源，然而乳品掺假现象时常发生，近年来尤以向乳品中掺假动、植物蛋白，向特色畜乳中掺假牛乳等方式为主，这不仅损害了消费者的利益，甚至会危害消费者的健康。该研究总结了目前常见的掺假行为及相关检测方法，并介绍了蛋白质组学技术——一种通过确立特定生物标记物来区别不同物种乳的技术。作者查询了国内外近十年来牛乳和特色乳掺假方面的研究报道，关键词设置为“蛋白质组学”、“乳品”、“真实性”、“生物标记物”等，按照奶畜乳类别将所得文献进行分类。分别对奶牛乳、羊乳、驼乳、水牛乳、牦牛乳、驴乳的掺假物、潜在标记物和检出限等方面进行了总结和分析，以期为乳品真实性鉴定和保障乳品质量安全提供有效的工作思路。     

酪蛋白质量分数作为乳品掺假检验指标的探讨

论述了我国乳品掺假的原因、方式和危害,以及掺假鉴定的必要性和重要性,分析了酪蛋白是牛乳中的特征性成分,根据乳品中酪蛋白占乳蛋白的质量比例（即酪蛋白质量分数）一般会稳定在77%～78%左右,提出了酪蛋白质量分数≥73%,可以作为乳品掺假检验的定量指标,探讨了国内外酪蛋白定量检测方法的研究现状。结果表明,等电点沉淀法无疑是一种适合我国国情的、操作简单的酪蛋白检验方法,对防治乳品掺假具有重要的现实意义,并通过分析提出了该检验方法所需研究的内容。     

生鲜牛乳真蛋白快速检测方法

建立生鲜牛乳中真蛋白快速检测方法,运用于牛乳中蛋白质掺假检测.采用紫外分光光度计,在280 nm波长处,通过吸光度值来测定真蛋白质量浓度:采用FT-120、甲醛滴定法、凯氏定氮法进行对比验证;考察人为添加非蛋白类含氮物质氯化铵、硫酸胺、尿素对真蛋白含量检测结果的影响.结果表明,紫外分光光度法检测真蛋白质量浓度与其他3种检测方法差异不显著;且检测结果不受人为添加非蛋白类舍氮物质的影响.紫外分光光度法检测生鲜牛乳真蛋白质量浓度,方法快速、可行,适用于生鲜牛乳中蛋白质掺假检测.     

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