苹果汁中展青霉素和羟甲基糠醛的高效液相色谱测定方法

为了建立能有效地将苹果汁中羟甲基糠醛分离的展青霉素高效液相色谱测定方法,将苹果汁样品用乙酸乙脂提取,提取液经碳酸钠溶液净化,无水硫酸钠脱水,再通过反相色谱柱检测。色谱柱为supelco C18柱,紫外检测器检测波长为275nm。结果表明:展青霉素和羟甲基糠醛能完全分离,其检出限均为5μg/L,加标回收率分别为73.1％～82.7％和78.8％～83.6％。从而建立了一个能有效分离羟甲基糠醛的准确、灵敏的展青霉素高效液相色谱测定方法。     

微波-甲基磺酸催化水解甘蔗渣制备糠醛的工艺研究

糠醛是一种重要的有机化工原料,有着广阔的应用前景。甘蔗渣富含多缩戊糖,可作为制备糠醛的原料,但甘蔗渣往往都是经干燥处理后用作燃料。本研究以甘蔗渣为原料,甲基磺酸为催化剂,在微波加热下,催化水解甘蔗渣制备糠醛。通过单因素实验法,探讨了反应时间、反应压力、液固比以及甲基磺酸浓度等因素对糠醛得率的影响,并采用正交实验法对糠醛的制备工艺进行优化。实验表明,影响糠醛得率的因素顺序为液固比〉反应压力〉甲基磺酸浓度〉反应时间,工艺较优条件为液固比89：1,反应压力1．3MPa,甲基磺酸浓度3．5%,反应时间12min。在此工艺条件下,糠醛最高得率为13．37％。     

小麦面粉中戊聚糖的化学分析测定法

将面粉试样与12％的盐酸溶液共沸，使样品中的戊聚糖水解，生成戊糖，戊糖脱水生成糠醛，再蒸馏出糠醛，并用四溴化法测定蒸馏出的糠醛含量，据此换算得出戊聚糖含量。     

紫外分光光度法测定白酒中糠醛的探讨

紫外分光光度法测定白酒中糠醛的探讨李君，田佩瑶，涂晓明食品与发酵工业，１９９４（５）：６４～６６糠醛，又称呋喃甲醛，它主要来源于谷壳和糠麸等酿酒原料。测酒中的糠醛，选择波长为２７７ｎｍ，于紫外分光光度计测定。选用５０％乙醇溶液作为无糠醛乙醇溶液，用于...     

高效液相色谱法测定浓缩果汁及水果果糖中5-羟甲基糠醛

建立了浓缩苹果汁、浓缩梨汁和水果果糖中的5-羟甲基糠醛的高效液相色谱（HPLC）检测方法。样品用甲醇溶解后,经水稀释,Inetrsil ODS-3 C18（250mm×4．6mm,5μm）色谱柱分离,紫外检测器在282nm处进行检测;5-羟甲基糠醛在1．0-25．0mg／L范围内线性关系良好,相关系数为0．9998,回收率为82．2％～103.3％,精密度（RSD）为0．62％-1．25％,方法的检出限（LOD）为0．2mg／kg。本方法具有快速、简单、灵敏度高、适用范围广等特点,可以满足果汁中5-羟甲基糠醛的分析要求。     

高效液相色谱同时测定啤酒中的5-羟甲基糠醛和糠醛

采用高效液相色谱（HPLC）同时分析啤酒中的5-羟甲基糠醛（HMF）和糠醛（2-F）。采用0．1％乙酸-乙腈为流动相,等度洗脱,样品中的5-HMF和2-F在10min内达到基线分离。啤酒样品直接进样测定,5-HMF和2-F的RSD分别为0．70％和1．09％（n=5）;平均加标回收率分别为101％和103％（n=3）。     

固相萃取-超高效液相色谱法测定浓缩石榴汁中羟甲基糠醛含量

建立了浓缩石榴汁中羟甲基糠醛(HMF)的超高效液相色谱(UPLC)检测方法.样品用水溶解后,用Bond Elut ENV固相萃取柱净化,UPLC HSS T3色谱柱分离,乙腈-水(8+92,V/V)为流动相,检测波长285nm,外标法定量.羟甲基糠醛的检出限为0.02mg/L,在0.1～10.0mg/L的浓度范围内标准溶液的浓度与峰面积线性关系良好,在10、20、50mg/kg三个添加水平下,回收率为80.8％～110.8％,相对标准偏差(RSD)低于8.1％.该方法简便、快速、准确,可用于浓缩石榴汁中羟甲基糠醛的检测.     

酒精发酵副产物对酵母菌生物的影响

探讨了乙酸、乳酸、焦糖色素及糠醛酒精发酵副产物对酵母菌生长和酒精发酵的影响。在酵母基本培养基中,加入乙酸、乳酸、焦糖色素及糠醋的量分别为0.1%、0.1%、2.0%和0.2%时,酵母细胞数减少50％。而在酵母基本培养基中同时添加乙酸、乳酸、焦糖色素及糠醛时,对酵母菌生长的抑制强度高达70％。酒精发酵的原料出酒率仅为正常发酵的50％。     

蒸汽爆破对烟梗化学成分含量及显微结构的影响

为评价蒸汽爆破对烟梗理化指标的影响,采用蒸汽爆破技术对烟梗进行处理,分析了在不同压力条件下,蒸汽爆破对烟梗常规化学成分含量、香味成分含量以及显微结构的影响.结果表明:①蒸汽爆破处理使烟梗中的还原糖和总糖含量降低,最大降幅分别为21.63％和23.46％;②蒸汽爆破促使烟梗中苯乙醛、糠醇、5-甲基糠醛、2-乙酰基呋喃和糠醛等香味成分含量增加,增幅分别为34.25％,102.97％,380.49％,76.24％和139.39％;③蒸汽爆破使烟梗显微组织结构疏松至破损,细胞壁呈现不规则撕裂,部分出现明显断裂,同时细胞间隙和细胞器物质消失.     

红提葡萄中香气成分的GC-MS分析

采用水蒸气蒸馏法提取红提葡萄的挥发性成分,利用GC-MS技术进行分析,分离并确定了53个组分,其中3-羟基-2-丁酮、1．羟基-2．丙酮、糠醛、2,4-二羟基．2,5．二甲基-3（2H）．呋喃酮）、丁内酯、糠醇、苯乙醇、糠酸甲酯、5-羟甲基糠醛、亚油酸乙酯、肉豆蔻酸、棕榈酸、棕榈烯酸、油酸、亚油酸和亚麻酸其相对含量分别为1．36％、1．79％、18．547％、7,04％、2,22％、1．07％、11．08％、3．524％、3．06％、1．11％、1,48％、12．21％、2．55％、4．11％、9．58％和4．34％。表明红提葡萄为一种非芳香型品种。     

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