超声波对小麦麸皮木聚糖的提取效果影响

麸皮是小麦加工过程中的副产品,含有丰富的具有生物活性的木聚糖。为了充分提高小麦麸皮的附加值,采用超声波法萃取其中的木聚糖。讨论了碱液浓度、液固比、超声功率、超声时间和温度对木聚糖提取率的影响,在此基础上进行正交试验分析。结果表明:在液固比25∶1(m L/g),Na OH溶液浓度0.5 mol/L,超声功率240 W,超声时间35 min和超声温度50℃条件下,可以获得提取率高达44.8%的麸皮木聚糖。利用超声波法提取小麦麸皮木聚糖成低、能耗小和效率高,具有重要的应用价值。     

碱液提取小麦麸皮木聚糖的研究

通过碱液浸提法及酸法干蒸与碱液浸提相结合两种方法，对已去除淀粉和蛋白质的小麦麸皮进行处理，提取木聚糖。并最终选取NaOH溶液浓度2％、料液比1：10、提取温度80℃、提取时间2h、60目麸皮为NaOH溶液浸提法提取木聚糖的试验条件。选取H2SO。溶液浓度0．1％、酸解时间8h、酸解温度60℃；蒸煮时间30min．蒸煮温度125℃；NaOH溶液浓度3％、碱液浸提时间2h、碱液浸提温度60℃为酸法干蒸与碱液浸提法相结合提取木聚糖的试验条件。     

麦麸品种与提取方式对阿拉伯木聚糖结构及抗氧化性的影响

目的：利用不同方式提取不同品种小麦麸皮中的阿拉伯木聚糖（arabinoxylan,AX）,对提取的AX进行结构表征并比较其抗氧化性。方法：分别利用碱提、超声辅助木聚糖酶提和超声辅助纤维素酶提法从不同品种小麦麸皮（‘百农207’‘百旱207’‘冠麦1号’‘华育198’和‘华育166’）中提取AX,测定其化学组成,对比其分子质量、分子结构、热稳定性及抗氧化性能。结果：3?种提取方式中,碱提法得率较高,且总糖质量分数较高;酶提法则能更大程度地保留多酚,这可能是酶提AX抗氧化性较好的原因,但在一定程度上降低了AX的分子质量,且酶提AX单糖组分比例与碱提AX差异较大,糖苷键连接方式也更复杂;两种酶提法相比,超声辅助木聚糖酶提AX得率和总糖质量分数更高,但超声辅助纤维素酶提AX多酚质量分数更高,且二者单糖比例及糖苷键连接方式也不同;此外,不同品种麸皮AX的分子质量、单糖比例、糖苷键连接方式及比例不同。结论：碱提、超声辅助木聚糖酶提和超声辅助纤维素酶提3种方法从小麦麸皮中提取得到的AX结构及活性存在明显差异,酶提法相对碱提法AX得率和分子质量较低,但多酚含量较高、抗氧化性能较好;超声辅助木聚糖酶提较...     

碱提条件对麸皮阿拉伯木聚糖组成、理化性质、流变学特性的影响

以碱提取法制备小麦麸皮阿拉伯木聚糖,采用高效液相色谱法、高效凝胶过滤色谱法和流变分析方法考察不同NaOH浓度、提取温度和提取时间对阿拉伯木聚糖的单糖组成、分子质量分布和黏度的影响。结果表明,随NaOH浓度的增加,阿拉伯木聚糖的纯度呈现先下降后上升的趋势,而得率则先上升后下降;随提取温度和时间的增加,阿拉伯木聚糖的纯度和得率均先增加后趋于平衡。在NaOH浓度、提取温度和提取时间分别为0.5 mol/L、85℃和120 min条件下所得阿拉伯木聚糖的纯度和提取得率分别为88.72%和32.8%。阿拉伯木聚糖的分子质量随提取温度的升高而明显减小;溶液的黏度随NaOH浓度的增加明显增大,随提取温度和时间的增加而显著减小。结果表明,不同碱提取条件所得阿拉伯木聚糖的性质差异较大,本实验可为麦麸阿拉伯木聚糖的碱提取和应用研究提供一定理论支持。     

超声波辅助碱法制备玉米芯木聚糖

以玉米芯为原料,经高温预处理后,采用超声波辅助碱法提取玉米芯木聚糖,在单因素实验的基础上,通过正交试验对玉米芯木聚糖提取工艺进行优化。结果表明:木聚糖的最佳制备工艺为氢氧化钠浓度7%,料液比1∶25,超声功率250 W,超声时间40 min,超声温度60℃。在此条件下,提取液中以玉米芯计还原糖的含量为64.10 mg/g,可溶性总糖含量为100.14 mg/g,木聚糖得率为9.01%。     

木聚糖提取优化及对木聚糖酶活性的影响

以小米糠为试验原料,研究小米糠中木聚糖的提取工艺及对肠道木聚糖酶活力的影响。在单因素的基础上,采用正交试验优化小米糠木聚糖提取工艺,研究料液比、碱提温度、碱液浓度、碱提时间4个因素对提取木聚糖提取率的影响。并采用着色木聚糖标记法测定木聚糖酶活力,研究小米糠木聚糖对大鼠肠道粪便及消化道木聚糖酶活力的影响。结果表明,小米糠木聚糖的最佳提取工艺:料液比为1∶25(g/mL),碱处理温度为100℃,碱液浓度为10%,碱处理时间为2 h,在此条件下木聚糖提取率为21.71%。     

小麦麸皮木聚糖制备方法的研究

研究了小麦麸皮木聚糖的制备,借助高速粉碎处理的方法分离麸皮中淀粉,再采用胶体磨与纤维素酶处理及碱浸泡处理,回收蛋白质,最后通过优化确定最佳低聚糖的最佳工艺。试验结果显示粉碎时间2 min,试验原料的粒径范围为125μm,淀粉得率72.43%;纤维素酶和碱处理的最佳工艺条件为:加酶量1.0 m L/hg,碱处理温度为60℃,碱处理p H为9.5,在此条件下木聚糖质量分数为35.5%,蛋白质提取率为74.9%,水洗的最佳水洗次数为4次,此时木聚糖质量分数为36.5%。     

提取条件对小麦麸皮阿拉伯木聚糖相对分子质量分布的影响

以小麦麸皮为原料,通过化学分析法和高效凝胶渗透色谱法,探讨提取时间、pH值和温度对阿拉伯木聚糖提取得率及其产品相对分子质量分布的影响。结果表明,随着提取时间的延长、pH值和温度的升高,阿拉伯木聚糖的得率显著提高。延长提取时间（5 h）,可以提高产品中低相对分子质量阿拉伯木聚糖的含量;提高反应的pH值（13.0）和温度（90 ℃）则可以获得富含多种高相对分子质量阿拉伯木聚糖的产品。     

超声波辅助碱提香菇柄中水溶性蛋白的工艺

以蛋白质得率为指标,研究液料比、pH、超声功率、超声温度及超声时间对蛋白质得率的影响,在单因素基础上,选取液料比、超声温度及超声时间为自变量,利用响应曲面法对超声波辅助碱提香菇柄中水溶性蛋白的提取工艺进行优化。结果表明,超声辅助碱提香菇柄中水溶性蛋白的最佳提取工艺条件为:液料比值16.8 mL/g,超声温度45.3℃,超声时间46.4 min。在此条件下,蛋白质得率达到2.87%。     

响应面法优化小麦麸皮中总酚含量的测定

响应面法优化小麦麸皮中总酚含量的测定,主要考察的因素有筛分孔径、福林试剂含量、Na_2CO_3质量分数和反应温度。450~900 nm波长扫描结果确定750 nm作为多酚含量检测波长。单因素试验及响应面试验结果表明:各个单因素对总酚含量的影响从大到小的顺序依次为福林试剂含量、筛分孔径、反应温度、Na_2CO_3质量分数;小麦麸皮中总酚含量测定的最佳条件为筛分孔径9.23XX、福林试剂含量5.39 m L、Na_2CO_3质量分数14.24%、反应温度29.36℃。在此条件下,测定的小麦麸皮中总酚含量为2.044 81 mg/g。     

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