大理百合多糖的醇沉分离工艺及脱蛋白方法

筛选出最佳的大理百合多糖的醇沉分离工艺及脱蛋白方法;比较在不同提取液浓缩比和乙醇加量条件下的多糖沉淀率,筛选出最佳的提取液浓缩比和乙醇加量。从蛋白质清除率和多糖损失率两方面对Sevag法和三氯醋酸法进行比较。对大理百合多糖,提取液∶浓缩液=3∶1(体积比),乙醇加量为4倍体积的浓缩液,Sevag法去除蛋白质为最佳醇沉工艺和脱蛋白方法。     

微波辅助法提取香菇多糖的工艺

研究微波辅助法提取香菇多糖并用离子交换树脂去除杂质蛋白的工艺方法.采用单因素试验对固液比、微渡辐射功率、辐射时间、乙醇用量以及杂蛋白的去除条件分别进行了考察.试验结果表明最佳提取工艺条件为:固液比1 g:20 mL微波辐射功率为280W,辐射时间5min,乙醇与多糖提取液体积比为4:1,香菇多糖提取率可达到9.46%;采用LX-67阴离子交换树脂在料液pH 9时可有效去除蛋白质杂质,多糖纯度可达到85%.     

超声波辅助乙醇提取玉米黄色素的工艺研究

以玉米黄粉为原料,研究玉米黄色素的超声波辅助乙醇提取工艺条件。首先进行单因素试验,以玉米黄色素提取液的吸光度值为指标,确定液固比、提取时间、提取温度及超声功率4个提取工艺参数的最适水平范围,再通过正交试验设计对上述4个工艺参数进行优化。结果表明超声波辅助乙醇提取玉米黄色素的最佳工艺条件为液固比25∶1、提取时间35min、提取温度60℃、超声功率160W。在此条件下玉米黄色素得率为7.3%,色价为18.2。稳定性研究结果表明,玉米黄色素对光不稳定,宜避光保存;该色素在70℃以下短时间保存较稳定,超过70℃降解速度较快;该色素在中性和碱性条件下较稳定。     

栀子黄色素微波提取工艺

对栀子黄色素微波提取工艺进行了研究。通过正交实验优化工艺条件,确定了栀子黄色素微波提取的工艺为提取液乙醇浓度50%、微波功率400W、提取时间90s、料液比1∶10、提取次数1次,色素提取率达94.14%。     

超声辅助提取柚子黄油胞层黄色素的研究

利用超声波的空化作用和响应面法进行优化柚子黄油胞层黄色素的提取工艺,建立了提取时间、料液比和乙醇浓度对黄色素提取的数学模型,优化出最佳提取工艺。结果表明:料液比、乙醇浓度对黄色素提取溶液的吸光度影响显著,最佳提取参数为提取时间30min、料液比1∶33g/m L、乙醇浓度51%,在此条件下柚子黄油胞层黄色素提取液的吸光度为1.778(n=3),与预测值无显著性差异。      

蒲公英黄色素提取工艺优化

以提取液吸光值为提取效果,通过分光光度计分析,确定70%乙醇为最佳浸提剂,提取液最大吸收波长λmax为440 nm。对蒲公英黄色素的提取进行了初步探索,优化蒲公英黄色素提取工艺,旨在开发新的天然色素资源,为工业化提取和精制蒲公英黄色素提供理论基础。通过超声处理,有机溶剂浸提法,选择无毒、无残留的乙醇作为浸提剂。通过回归正交旋转组合设计实验表明,料液比和浸提温度对蒲公英黄色素的提取影响较大。在优化条件下料液比1∶40(g/mL)、温度50℃、乙醇浓度70%下测得的最大OD值为0.816。     

阿魏菇多糖的分离纯化与结构分析

通过对新疆阿魏菇多糖进行提纯及分析,了解其基本理化性质,在理论上为深入探究阿魏菇多糖的结构以及构效活性奠定了基础。阿魏菇的热水提取液经乙醇沉淀、去蛋白、逆向流水透析、DEAE-Cellulose和SephadexG-100柱层析得纯品阿魏菇多糖。薄层色谱分析表明阿魏菇总多糖是由半乳糖,葡萄糖,果糖,甘露糖组成。以红外和电泳为基础,分析了阿魏菇多糖组分的结构,表明其是一种较纯的多糖,原子力显微镜分析表明阿魏菇多糖分子具有高度分枝结构。     

酸枣果肉多糖的提取工艺和抗氧化研究

目的:研究酸枣多糖的提取工艺和抗氧化作用。方法:采用甲醇-乙酸乙酯回流脱色及除去小分子杂质,对提取温度、pH、提取时间及乙醇沉淀比例进行正交实验,以苯酚-硫酸法测定多糖含量;对所提取酸枣多糖给小鼠灌胃30d,测定血中SOD、CAT活性和MDA含量。结果表明,提取前用甲醇-乙酸乙酯回流对多糖得率没有影响。对酸枣多糖提取率影响最大的因素是温度,其次是提取时间和沉淀乙醇比例,提取液pH影响不明显。提取因素以85℃、3h、pH8组合较为合适。酸枣多糖可提高小鼠血中SOD和CAT水平,可降低血中MDA水平,但不显著。综合分析,酸枣多糖对所试动物具有抗氧化作用。      

基于遗传算法的橘皮黄色素提取工艺优化

为优化橘皮黄色素的提取工艺,对料液比、超声时间、超声温度、乙醇浓度进行了单因素试验和正交试验,摸索出参数优化范围,并在此基础上利用遗传算法对提取条件进行优化,结果表明,当料液比为1∶16,超声时间为59 min,超声温度为62℃,乙醇浓度为78%时,工艺验证试验结果为橘皮黄色素提取液稀释液的吸光度达到0.73,该结果可信度较高,为提高橘皮黄色素的提取效率提供了新的思路。     

大蒜素纳滤纯化工艺研究

大蒜素纳滤纯化工艺可有效除去大蒜乙醇提取液中糖类等杂质,获得的产品中大蒜素含量比单纯乙醇浸提浓缩工艺提高了8倍,达到13.4%,大蒜素得率为0.18%。适宜的纳滤纯化工艺条件为:150 u纳滤膜,压力0.6 MPa,温度30~35℃。     

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