非水相中脂肪酶催化合成乙酸薄荷酯

研究了脂肪酶（candida rugosa lipase,CRL）在有机溶剂中催化薄荷醇与乙酸进行酯化反应的条件。探讨了脂肪酶加入量、溶剂、薄荷醇与乙酸摩尔比、底物浓度、温度等因素对脂肪酶催化合成乙酸薄荷酯的影响,并利用红外光谱、GC-MS、气相色谱等方法对合成的产物进行了表征。结果显示,合成的产物为乙酸薄荷酯。当溶剂为正己烷、脂肪酶量为1.2%（脂肪酶在薄荷醇和乙酸体系中的质量分数）、薄荷醇与乙酸的摩尔比为1∶1、薄荷醇与乙酸的底物浓度均为0.1mol/L、温度为40℃、反应48h时,乙酸薄荷酯的酯合成转化率达92.4%。产物乙酸薄荷酯的色泽好、气味纯正。      

顶空气相色谱法测定薄荷型卷烟中的薄荷醇

建立了一种测定薄荷型卷烟烟丝、滤嘴和纸张中薄荷醇的静态顶空气相色谱方法。样品经100℃、30 min顶空加热后,用HP-INNOWax色谱柱分离、氢火焰离子化检测器检测和内标法定量。结果表明:1该方法精密度好,线性范围广,检出限和定量限分别为3.3和11.1μg/mL,回收率为92.7%~103.4%,相对标准偏差(RSD)小于7%(n=6)。2该方法的测定结果与行业标准气相色谱法的结果一致。3具有简单、快速、准确、自动化及溶剂消耗少等优点。该方法适用于生产和储存期间薄荷型卷烟品质控制中对薄荷醇含量的快速大批量检测,并可用于储存期间小盒包装中薄荷醇的分布研究。     

鱼露风味成分的萃取及气相色谱分离条件的优化

本实验对鱼露风味物质的萃取溶剂及气相色谱分析条件进行了初步研究.实验结果表明:乙酸乙酯是最适于萃取鱼露风味物质的溶剂;用单因素试验优化的鱼露风味物质的气相色谱分析条件为:毛细管色谱柱CP-Sil-8cb,载气为99.999%的氮气,载气的柱流速为3ml/min,进样量为1 μl,分流比为100:1,氢气流速为30ml/min,空气流速为300m/min,尾吹气流速为27ml/min,初始柱温为30℃,以5℃/min程序升温至120℃,继续以12℃/min程序升温至180℃,保持4min,进样口温度为200℃,FID检测器的温度为250℃.在此条件下,共有44种成分得到了分离,其中24种成分达到了基线分离.     

非抑制型电导检测离子排斥色谱法测定江西白酒中的有机酸

建立了非抑制型电导检测离子排斥色谱法分离并测定6种有机酸(草酸、酒石酸、苹果酸、甲酸、琥珀酸、乙酸)的方法.以Ion Pac ICE-AS6色谱柱为分离柱,选用背景较低的稀苯甲酸溶液为淋洗液,考察了淋洗液浓度、流速、色谱柱温度对分离和测定有机酸的影响.通过实验确定最佳的色谱条件为:1.0mmol/L苯甲酸溶液作为淋洗液,流速0.45ml/min,柱温35℃.所测有机酸的检测限为0.0341～0.9045mg/L,相对标准偏差在0.13%～5.12%之间(n=5),回收率为90.75%～108.5%,方法具有较好的准确度和精密度.该法用于江西5个不同生产厂家23个白酒样品中有机酸的测定,结果令人满意.     

食用酒中甲醇气相色谱分析方法研究（一）—ODPN用于食用酒中MeOH测定的色谱条件研究

选用ODPN作用定相，采用表态项空以样技术对食用酒中MeOH进行测定，结果表明，该法准确度高，重现性好，平均分析周期7.55min，其分析速度是国际（GDX－102柱）的2．28倍，是一简便，快速，准确的MeOH测定GC法，它的建立加强对酒类市场的及时监督具有重要的意义，对ODPN用于食用酒中MeOH的分析进行了研究，通过3种固定液的比较，结果显示，ODPN能较好的分离食用酒中的MeOH,对几种不同ODPN含量的柱子进行对比研究，色谱柱ODPN含量取10％，对所制柱子的色谱条件进行系统研究，最适色谱条件为，N2流速35ml/min,H2，流速25ml/min,Air流速300ml/min,柱温45℃，汽化温度100℃，检测器温度120℃。     

串联毛细管手性柱分离薄荷醇的8 种光学异构体

为分离和检测食品和药品中的薄荷醇旋光异构体，通过详细研究非手性毛细管柱和手性毛细管柱对8 种薄荷醇旋光异构体的分离效能，建立串联手性毛细管色谱柱分离、气相色谱-质谱法定量检测糖果食品和药品中8 种薄荷醇旋光异构体的方法。结果显示：无特殊选择性固定相的DB-5MS、DB-624、DB-ALC1、DB-INNOWAX毛细管柱均能实现D/L-薄荷醇、D/L-新薄荷醇、D/L-异薄荷醇、D/L-新异薄荷醇4 对对映异构体的分离，但不能实现其D型和L型旋光异构体的分离。结合CycloSil-B、BGB-175手性毛细管柱分离薄荷醇异构体的互补能力，采用CycloSil-B＋BGB-175串联手性毛细管柱，成功分离了8 种薄荷醇旋光异构体，色谱峰均达到分离要求，峰形尖锐对称，响应值和保留时间具有较好稳定性，分离条件下柱流失较小，对薄荷醇检测无明显影响。建立了糖果食品和药品中8 种薄荷醇旋光异构体的定量测定方法，方法的定量限为23.0～72.9 μg/L，加标回收率为86.0%～116.0%。该方法成功用于糖果食品和药品中薄荷醇旋光异构体的分离和检测，结果显示所有样品中检测到的薄荷醇均以L-薄荷醇为主，大部分样品中检测到微量的其他薄荷醇异构体，并可通过薄荷醇异构体构型组成对不同样品中薄荷醇类型进行区分。     

高效液相色谱法测定魔芋精粉中魔芋葡甘聚糖含量

首次建立了HPLC法测定魔芋精粉中魔芋葡甘聚糖(KGM)含量的方法。魔芋精粉水解条件:温度100℃、时间2.5h,H2SO4浓度2mol/L;色谱条件:色谱柱SugarPakⅠ;流动相重蒸水,流量0.4ml/min,柱温90℃,进样量10μl。结果表明,上述条件下杂质成分以及Glu及Man之间可完全分离。该方法测定KGM的平均回收率为99.05%,相对标准偏差为0.58%,同时可以测定精粉中的淀粉含量,可用于葡甘聚糖的定量分析和魔芋精粉的质量评价。     

高效液相色谱法测定魔芋精粉中魔芋葡甘聚糖含量

首次建立了HPLC法测定魔芋精粉中魔芋葡甘聚糖(KGM)含量的方法。魔芋精粉水解条件:温度100℃、时间2.5h,H2SO4浓度2mol/L;色谱条件:色谱柱SugarPakⅠ;流动相重蒸水,流量0.4ml/min,柱温90℃,进样量10μl。结果表明,上述条件下杂质成分以及Glu及Man之间可完全分离。该方法测定KGM的平均回收率为99.05%,相对标准偏差为0.58%,同时可以测定精粉中的淀粉含量,可用于葡甘聚糖的定量分析和魔芋精粉的质量评价。      

白酒中乳酸的离子排斥色谱-直接电导检测分析

建立用直接电导检测的离子排斥色谱分离测定乳酸的方法。以Shim-pack SCR-102H色谱柱为分离柱,用对p-甲苯磺酸为流动相,考察流动相浓度、色谱柱温度及流速对分离和测定乳酸的影响。最佳色谱条件为以2.0mmol/L p-甲苯磺酸为流动相、流速1.0mL/min、柱温50℃。在此条件下,乳酸的保留时间约为8min,其他有机酸(甲酸、乙酸、柠檬酸和苹果酸)不干扰测定。乳酸的检出限为0.36mg/L,工作曲线的线性范围是1.0～100.0mg/L,峰面积的相对标准偏差(n=5)为0.9%。将方法应用于测定白酒中的乳酸,加标回收率为95.8%～98.5%。     

HPLC法测定酒糟水解液中单糖、有机酸和糖醛酸的研究

建立了HPLC法(高效液相色谱法)测定酒糟水解液中单糖、有机酸和糖醛酸含量的分析方法。色谱条件:色谱泵为P200Ⅱ高压恒流泵,Aminex HPX-87H柱,检测器为Waters 450示差折光检测器,柱温50℃,流动相为4 mmol/L的硫酸,流速为0.5 mL/min,进样量10μL,外标法定量。在此条件下葡萄糖、阿拉伯糖、鼠李糖、甲酸、乙酸、葡萄糖醛酸、半乳糖醛酸分离状况良好,其峰面积与浓度线性关系良好,相关系数R值在0.9912～0.9997之间,回收率为99.40%～105.90%。在Aminex HPX-87H柱上不能分离的木糖、半乳糖、甘露糖用大连依利特HYDERSIR-NH2色谱柱,柱温35℃,检测池温度35℃,流动相为乙腈:乙酸乙酯:水=60:25:15(v/v),流速0.6ml/min,进样量10μL,外标法定量。其峰面积与浓度线性关系良好,相关系数R值在0.9959～0.9991之间,回收率为99.99%～102.70%。     

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