高效液相色谱-蒸发光散射检测器分析配方乳粉中的低聚果糖

建立了高效液相色谱-蒸发光散射检测器检测配方乳粉中低聚果糖的方法,采用水和乙腈二元梯度淋洗,在28min内梯度洗脱,低聚果糖(蔗果三糖、蔗果四糖、蔗果五糖)分离效果好,蔗果三糖、蔗果四糖、蔗果五糖的平均回收率分别为84.4%、74.3%、69.5%,方法简便快速,结果准确可靠,可以用于配方乳粉中低聚果糖的检测。     

高效液相色谱-蒸发光散射检测法快速测定益生菌粉中低聚果糖含量

目的建立高效液相色谱-蒸发光散射检测(HPLC-ELSD)法,快速洗脱分离出蔗果三糖、蔗果四糖、蔗果五糖,测定益生菌粉中低聚果糖的含量。方法样品经过前处理,以乙腈和水为流动相,等度洗脱,经XAmide(4.6 mm×250 mm,5μm)中性酰胺色谱柱分离,采用蒸发激光检测器检测。结果蔗果三糖、蔗果四糖、蔗果五糖线性范围分别在0.2671~3.168 mg/m L、0.2429~2.8215 mg/m L、0.1617~3.544 mg/m L,线性相关系数r0.99。3种主要组成的回收率在97.0%~105.0%之间。结论该方法可有效分离出蔗果三糖、蔗果四糖、蔗果五糖,推广性高、快速、简便、准确,可用于益生菌粉中低聚果糖含量的测定。     

高效液相色谱串联质谱法测定乳粉中低聚果糖

建立了测定乳粉中低聚果糖(蔗果三糖、蔗果四糖、蔗果五糖、蔗果六糖)的高效液相色谱串联质谱(HPLC-MS/MS)检测方法。乳粉样品用乙醇-水提取,上清液稀释后,采用XBridge TM Amide(3.5μm,4.6 mm×150 mm)柱,以乙腈-氨水溶液为流动相进行洗脱,电喷雾质谱负离子(ESI-),多反应监测(MRM)模式检测,外标法定量。该方法在0.5~20 mg/L范围线性良好(r0.9990,检出限最低为0.022 mg/kg)。分别在样品中添加标准物质1、5、10 mg/kg进行回收率实验,方法的回收率范围为90.8%~95.8%,相对标准偏差为3.6%~9.0%(n=6)。该方法样品前处理简单、快速,分析时间短,灵敏度、准确度和精密度均满足乳粉中低聚果糖的检测要求。     

利用蒸发光散射检测器测定食品中的低聚果糖

采用高效液相色谱-蒸发光散射检测器在同一色谱条件下对不同种类食品中低聚果糖含量的测定。结果表明,在该检测条件下,食品中低聚果糖组分的能够得到有效的分离,基线平稳。蔗果三糖、蔗果四糖、蔗果五糖的检测范围在0.67mg/m L~14.0 mg/m L之间,线性相关系数在99.95%以上。不同种类的食品样品中,低聚果糖3种组分的回收率在95.20%~100.15%之间。该方法灵敏度高,准确,快捷,适合于食品中低聚果糖含量的测定。     

食品中低聚果糖高效液相色谱检测方法研究

针对乳制品、糕点、酒类、饮料、糖果等食品中添加的功能活性成分低聚果糖,包括蔗果三糖(GF2)、蔗果四糖(GF3)、蔗果五糖(GF4)的检测,建立了水和乙腈为流动相,梯度洗脱,氨基色谱柱分离,蒸发光散射检测器(evaporativelight-scattering detector,ELSD)检测食品中添加的低聚果糖含量的高效液相色谱方法。蔗果三糖、蔗果四糖、蔗果五糖的线性工作范围分别为0·04~0·45、0·05~0·50、0·04~0·45mg/mL,线性相关系数R2分别为0·9999、0·9999、1。对不同类型的食品,三种低聚果糖的回收率在90·0%~110·0%之间,方法准确度高。室内重复性变异系数一般都低于10%,室间再现性变异系数一般都低于15%,说明方法的重复性和再现性良好。该方法简单、易于掌握,测定结果准确,适于复杂食品基质中低聚果糖含量的测定。     

乳制品中单糖、双糖和低聚果糖的同时测定

建立了高效液相色谱同时分离测定乳制品中果糖、葡萄糖、蔗糖、乳糖、蔗果三糖、蔗果四糖、蔗果五糖等7种糖的方法。通过调节样品溶液的p H值到1.7和4.5除去样品中蛋白质,采用氨基色谱柱,以乙腈-水为流动相梯度洗脱,用蒸发光散射检测器检测。7种糖质量浓度在0.01~10.0 mg/m L内具有良好的线性关系,回收率在95.0%~104.1%,精密度(RSD)为1.98%~4.56%,检出限在0.04~0.17 mg/g。该方法可用于乳制品中单糖、双糖和低聚果糖的日常检测。     

奶粉中低聚果糖质量浓度的测定

为检测奶粉中低聚果糖的质量浓度,建立起奶粉中低聚果糖的正相高效液相色谱法.样品经质量浓度为100g/L硫酸铜和40g/L氢氧化钠去除蛋白,氨基色谱柱分离,示差折光检测器,柱温30℃,流速1 mL/min,流动相为乙腈:水=70∶30(体积比),标准曲线法定量.蔗果三糖、蔗果四糖、蔗果五糖在质量浓度范围内线性关系良好,添加回收率分别是99.1％,99.7％,95.3％,方法的精密度的相对标准偏差为0.3％,1.1％和0.3％,检出限为2,2,4mg/kg.该方法快速灵敏,简便准确,适用于奶粉中低聚果糖质量浓度的检测.     

运动饮料中糖分的检测

建立一种用高效液相色谱-蒸发光检测法测定运动饮料中常用的木糖、果糖、葡萄糖、半乳糖、蔗糖、麦芽糖、乳糖、蔗果三糖、蔗果四糖、蔗果五糖等10种糖分的检测方法。样品经乙腈-水提取,过滤膜后上机检测。采用ZORBAX糖分析色谱柱(4.6 mm×250 mm,5μm)分离,以乙腈-水梯度洗脱作为流动相,用蒸发光检测器检测,外标法峰面积定量。结果表明,10种糖组分在0.01 g/100 m L~0.50 g/100 m L浓度范围内线性良好,相关系数r2为0.996~0.999,检出限为0.02 mg/m L~0.1 mg/m L,定量限为0.06 mg/m L~0.3 mg/m L,加标回收率达到90.2%~98.5%。     

HPLC-ELSD法检测液态奶中的低聚半乳糖

建立一种检测液态奶中低聚半乳糖的方法.样品通过β-半乳糖苷酶、葡萄糖氧化酶-过氧化物酶处理,采用高效液相色谱-蒸发光散射检测水解溶液中的半乳糖含量,计算出样品中低聚半乳糖的含量.结果表明:该方法的检出限为0.10 mg/mL,回收率为87.5%～108.3%.该方法适合于分析液态奶中低聚半乳糖含量的检测.     

高效阴离子交换色谱法同时测定菊粉酶解产物中的单糖、双糖和低聚果糖

建立了低聚果糖样品中的葡萄糖、果糖、蔗糖、蔗果三糖、蔗果四糖和蔗果五糖的高效阴离子交换色谱-脉冲安培法的定量分析方法。采用阴离子交换柱CarboaPacTM PA10（250 mm×2 mm）脉冲安培法进行检测,以氢氧化钠和醋酸钠为淋洗液进行梯度洗脱,柱温30 ℃,流速0.3 mL/min。结果表明,葡萄糖、果糖、蔗糖、蔗果三糖、蔗果四糖和蔗果五糖在质量浓度0.1～10 mg/L范围内的线性关系良好,相关系数r2大于0.996 1,各组分的相对标准偏差均在2.69%～7.21%之间。将此方法应用于菊粉酶解后反应产物的检测,结果表明该方法快速简便且灵敏度高,能满足反应样品中低聚果糖的检测要求。     

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