反相高效液相色谱法测定果醋中的8 种维生素

建立梯度洗脱反相高效液相色谱法同时检测果醋中VC、VB1、VB2、VB3、VB6、VB12、叶酸和烟酰胺8种水溶性维生素的分析方法。考察柱温、缓冲液浓度、pH值以及梯度洗脱程序对各组分分离的影响。最终采用0.1mol/L醋酸钠溶液(pH4.25)和甲醇作为流动相进行梯度洗脱,流速为1.00mL/min,柱温为30℃,8种水溶性维生素在14.2min内达到基线分离;紫外检测波长为266nm和280nm;线性范围：VB2、叶酸为0.05～12.5μg/mL;VC、VB1、VB3、烟酰胺为0.1～25μg/mL;VB6、VB12为0.15～37.5μg/mL,相关系数均在0.999以上,其最低检出限为0.47～3.46ng/mL。该法被成功地用于定量果醋中的维生素,平均加标回收率为92.4%～105.2%,相对标准偏差为0.08%～1.54%。     

小米中VB2的提取方法研究及其含量的测定

通过单因素试验和正交试验分析研究不同提取液、提取方法和提取条件对小米中VB2 提取效果的影响。采用荧光分析法,在激发波长λex=471.0nm 和发射波长λem=528.0nm 时,测定小米中VB2 的含量。结果表明：选取H3PO4 溶液为提取液,用水浴回流法,提取液浓度0.1mol/L、提取时间45min、提取液pH5.0 时,提取效果最佳,且回收率可达到89.20%～100.32%,变异系数可控制在1.21% 内。实验精密度和准确度良好,可快速、准确的测定小米中VB2 含量。     

离子对反相高效液相色谱法同时测定功能性饮料中的B族维生素

建立了可同时测定VB1、VB2、VB6、VB12和烟酰胺等常见添加B族维生素含量的离子对反相液相色谱法.流动相为甲醇-醋酸(0.5%)(体积比30:70其中每升流动相含5 mmol的庚烷磺酸钠和0.05%三乙胺);流速为1.2 mL/min;采用紫外检测器,波长为270 nm;色谱柱为ZORBAX Eclipse XDB-C18,柱温为30℃.各种维生素含量测定方法的线性关系良好,R=0.9993～0.9998;回收率96.8%～100.2%,RSD=0.65%～1.43%.本方法应用于市售功能性饮料中B族维生素含量的测定,结果准确.     

高效液相色谱法测定茶叶中五种水溶性维生素

用高效液相色谱(HPLC)梯度洗脱法测定茶叶中的5种水溶性维生素成分和含量,结果表明,样品经XDB-C18柱分离,使用紫外检测器(波长266 nm),流动相为甲醇与0.03 mol/L KH2PO(4pH=6.1)混合,梯度洗脱,样品中5种水溶性维生素得到良好分离,该5种水溶性维生素标准曲线相关系数均达0.999 0以上,平均回收率为84.5%~102.7%,变异系数RSD<5.4%。测得普洱茶中VC的含量为14.37 mg/100g,VB1的含量为2.17 mg/100 g,VB6的含量为1.58 mg/100 g,VB2的含量为3.47 mg/100 g,叶酸含量为1.34 mg/100 g;信阳毛尖中VC的含量为11.69 mg/100 g,VB6的含量为1.76 mg/100 g,VB2的含量为8.12 mg/100 g,叶酸含量为9.66 mg/100 g,未检出VB1。     

HPLC测定小米中非法添加姜黄素及不确定度分析

采用高效液相色谱法(HPLC)对小米中非法染色姜黄素进行定性定量测定,并对其不确定度进行分析。以乙腈-4%冰乙酸(45+55)为流动相,流速1.0 mL/min,经C18柱分析,检测波长425 nm。采用外标法定量,姜黄素在0.585μg/mL~4.88μg/mL范围内线性关系良好,相关系数r~2=0.999 9,平均回收率92%,检出限为0.08 mg/kg,整个试验的合成不确定度为1.937%,扩展不确定度为X=(7.15±0.29)mg/kg;k=2。本方法操作简单,重复性好,检出限低,可用于小米中姜黄素非法染色的测定。     

新型高效液相色谱法分析淮山中的VB1

采用超声波提取法从新鲜淮山中提取VB1,研究高效液相色谱法分析淮山中VB1的最佳分析条件.结果表明:以甲醇:纯水=5:5为流动相,流动相的流速1.0 mL/min,紫外检测波长265 nm,柱温在25℃为淮山中VB1的最佳高效液相色谱分析条件,其标准曲线具有良好的线性关系,相关系数R2=0.998 9.在此条件下VB1的平均回收率为97.3%,重复性相对标准偏差小于4.8%;测得淮山中VB1的含量为3.8 mg/100 g.所建立的方法简单、快速、准确度高.     

小米绿豆清凉饮料加工工艺研究

选用α-淀粉酶和木瓜蛋白酶分别酶解小米和绿豆制取小米汁、绿豆汁,再以此为主要原料,用科学的调配方法研制具有清热解暑等作用的功能性饮料.小米汁的最佳酶解工艺为料液比1:4,在100℃下,糊化20min后,加入α-淀粉酶0.5%,pH为6.5,温度印℃,时间80min.绿豆汁最佳酶解工艺为料液比1:10,木瓜蛋白酶0.02%.pH为6.5,温度50℃,酶解时间100min.小米绿豆清凉饮料的最佳配方为绿豆汁:小米汁为6:4,白砂糖10%,食0O.1%,柠檬酸0.12%,最终清凉饮料成品中可溶性固形物为11%,总酸为0.53%,还原糖含量为4.49%,总黄酮含量为3.920μg/100mL氨基酸含量为22.9mg/100mL.     

高效液相色谱法测定强化面粉中VA

建立了高效液相色谱(HPLC)测定强化面粉中维生素A含量的方法.样品用水-甲醇(5 10)提取,提取液用正己烷萃取,萃取液直接用于色谱测定.实验以Chrosorb-60硅胶柱作为分离柱,经对色谱分离条件优化,最佳色谱分离条件为流动相为正己烷-异丙醇-乙酸比例为194∶5∶1(V/V/V);流速为1.0mL/min;检测波长为326nm.实验结果表明,方法三水平样品回收率(n=5)为98.18%～100.72%;八次重复性实验相对标准偏差(RSD)为1.26%;检出限(S/N=3)为5ng.     

方便面中丙烯酰胺含量的检测

建立了方便面中丙烯酰胺的液相色谱-串联质谱分析方法.样品用水提取,酶解,净化.以水(0.1%甲酸):乙腈=90:10(V/V)为流动相经反相色谱柱分离后,采用液相色谱串联质谱多反应监测正离子模式检测,丙烯酰胺定性定量离子对为m/z72.10/55.00,同位素内标物定性定量离子对为75.00/58.00.空白样品及其添加实验结果表明,特征离子相对强度比值稳定,无基质干扰,结合保留时间可实现准确的定性定量,方法检出限为25μg/kg(S/N=3),样本添咖水平在5～200μg/kg时,平均回收率为68.1～90.1%,相对偏差(n=6)为4.3%～6.1%.该方法前处理简单、回收率高、精密度好,可满足方便面中丙烯酰胺的确证分析要求.     

青藏高原白刺、枸杞和沙棘果粉中水溶性维生素含量比较分析

采用高效液相色谱(HPLC)法对青藏高原白刺、枸杞、沙棘果粉中的7 种水溶性维生素进行分析测定。结果表明：一次提取、分离可同测定7 种水溶性维生素的含量,加标回收率在88.0%～113.4% 之间,相对标准偏差在1.1%～9.0% 之间;3 种果粉的VC、VB1、VB2 含量差异显著,VC 含量高低顺序为沙棘果粉＞白刺果粉＞枸杞果粉,沙棘、白刺果粉VC 含量丰富,分别高达(18266.4 ± 201.1)、(1468.5 ± 24.6)mg/kg;VB1 含量高低顺序为枸杞果粉＞白刺果粉＞沙棘果粉;VB2 含量高低顺序为白刺果粉＞枸杞果粉,而沙棘果粉未检出VB2;VB6、VB12、烟酸、叶酸均没有检出。     

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.     

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.     

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