连翘花黄色素的提取及其对光热稳定性的研究

研究了连翘花中黄色素的提取方法 ,并对色素溶液在光照及加热等条件下的稳定性进行了初步研究。结果表明 :该黄色素易溶于乙醇、乙醚、乙酸乙酯等有机溶剂。当选用乙醇为溶剂时 ,色素提取的最佳条件为 :在 70℃、用 1g干花加 10 0mL体积分数为 95 %的乙醇的料液比浸提 3次、每次浸提 2h ,可将色素基本提取完全。该色素对强光的稳定性很差 ,而对弱光及热有较好的稳定性。不同波长的光对色素稳定性的影响也不相同。     

小米黄色素的研究Ⅱ-提取工艺及稳定性

开发研究了小米黄色素，对其提取工艺条件及几种提取剂进行了筛选，确定了最佳提取工艺条件为：95％乙醇为最佳提取剂；v（乙醇）：m（小米）=3：1，室温提取3～4次，每次2～4h。研究了光、热、氧化剂、还原剂、金属离子以及几种常用食品添加剂对小米黄色素稳定性的影响，结果表明：该色素溶液的最大吸收波长为445nm；具有一定的耐热性、耐还原性和耐氧化性；但耐光性差，宜避光保存；Fe^3＋对色素有破坏作用，K^＋、Na^2＋、Ca^2＋、Mg^2＋、Zn^2＋、Cu^2＋、Fe^2＋无不良影响；可与Vc、蔗糖和柠檬酸等食品添加剂调和使用。     

玉米黄色素的超声强化提取及其稳定性研究

以生产玉米淀粉的副产品玉米蛋白粉为原料，利用超声波技术，用不同的有机溶剂从玉米蛋白粉中提取玉米黄色素。最佳工艺条件为以95％乙醇作为提取溶剂，提取温度为50℃，超声时间为1．5h，玉米黄色素与95%乙醇的固液比为1g：15mL，pH值为7，提取收率可达8．7％。对玉米黄色素的稳定性和其抗菌活性进行了研究。结果表明：玉米黄色素水溶性较好，色素溶液对光、热比较稳定；在酸碱、金属离子、氧化剂、蔗糖等添加剂中具有较好的稳定性；但在含氧酸根阴离子、还原剂、维生素C、苯甲酸钠、山梨酸钾等添加剂中稳定性较差。     

微波萃取花生壳天然黄色素及其稳定性研究

本文对福建产花生壳进行微波萃取天然黄色素及其稳定性研究。研究表明微波萃取的工艺条件是：以pH=3,体积分数70％的乙醇水溶液作提取剂，原料与提取剂配比为1g:5ml，微波辐射功率120W辐射时间200s。对该色素稳定性研究的结果表明，该色素为水溶性色素，属黄酮类以素，适用pH值范围比较广，尤其性状态效果最佳，对光、热稳定性好，大多数食品添加剂对色素稳定性影响不大，对氧化剂H2O2的耐受能力较差，对还原剂Na2SO3的耐受能力强。     

树莓色素稳定性初步研究

研究树莓色素的提取方法、理化特性及其稳定性，利用色素的光谱性质，研究该色素对酸碱的稳定性、耐热性及常用食品添加剂、不同金属离子对其稳定性影响，结果说明：树莓色素为水溶性色素，易溶于水及有机溶剂如乙醇、丙酮、乙醚溶液，利用丙酮提取可以获得较高的提取率，同时具有较强的稳定性。     

芒果叶中黄色素的提取及其稳定性研究

以芒果叶为原料,采用正交实验,建立了从芒果叶中提取黄色素的最佳工艺条件,并分析了该色素的稳定性.结果表明:提取溶剂为体积分数60%乙醇,料液比1:9(g:mL),提取温度60℃,提取时间1.5 h,提取次数为2次,浸提率为81.23%.芒果叶黄色素对酸、热稳定,Na 、Zn2 、氧化剂及食品添加剂(葡萄糖、柠檬酸、苯甲酸钠)对色素无影响,Fe3 、Cu2 和Vc对色素有一定影响.     

芒果皮黄色素的超声波辅助提取及其稳定性的研究

采用超声波辅助提取法对芒果皮中黄色素的提取工艺进行了研究,同时,对黄色素的稳定性进行分析.实验结果表明,提取的最佳条件为:提取剂浓度95%,功率300W,提取时间10min.芒果皮黄色素对热稳定;Na+、Ca2+、Mg2+、氧化剂(H2O2)、还原剂(抗坏血酸)及食品添加剂(葡萄糖、柠檬酸)对色素影响较小;Fe3+、Cu2+、Zn2+、Al3+、Na2S2O3、苯甲酸钠和淀粉对色素有一定影响;色素在过酸过碱条件下不稳定.     

超声提取黄柏黄色素的研究

采用超声波法从黄柏中提取黄色素。结果表明,黄柏黄色素的最大吸收波长为335nm。最适宜提取剂为乙醇。最佳提取条件为：提取剂浓度60％、提取剂pH3～7、提取温度0℃。该色素耐光、耐热性强,常用的食品添加剂以及金属离子Na＋、Cu2＋、Mg2＋、Ca2＋等对色素无明显影响。     

龙眼果皮黄色素提取工艺及稳定性的研究

对龙眼果皮黄色素的提取工艺及稳定性进行了研究，结果表明：以0．1％HCl 95％乙醇1：1溶剂配比作为提取剂，固-液配比为5：95，温度为70℃，提取时间为2h是最佳提取工艺条件，在此条件下提取的龙眼果皮色素提取率最高，达到1．25％。龙眼果皮黄色素在弱酸、温度低于60℃下较稳定，但强酸、强碱、光照、高温及氧化还原剂等对其稳定性有一定影响。     

沙枣黄色素的提取及稳定性的研究

对沙枣黄色素的提取及稳定性进行了系统研究,结果表明:沙枣黄色素的最大吸收波长λmax=322nm,从沙枣中提取色素的最佳工艺条件为:以pH3的70%的乙醇为浸提剂、提取温度为50℃、提取时间3h、液料比为1∶35。该色素耐光、耐热,氧化剂、还原剂和常用的食品添加剂蔗糖、苯甲酸钠、碳酸氢钠对色素稍有影响,金属离子Cu2 、Fe3 、Zn2 、Na 、Ca2 、K 离子对色素都有增色作用,Mn2 对其有减色作用。     

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