微波法萃取玉米黄色素的工艺

采用微波萃取技术提取玉米黄色素,研究微波控制条件对玉米黄色素提取率的影响,并在单因素试验的基础上进行正交试验.研究结果表明,玉米黄色素的最大吸收波长为448nm,微波萃取玉米黄色素的最佳工艺条件为以50％乙醇为提取溶剂,微波功率450W、料液比为1:12(g:mL)、微波作用时间80s、萃取2次.     

玉米黄色素提取工艺及其抗氧化活性研究

以玉米糁为原料,通过单因素和正交试验,考察浸提温度、浸提时间、乙醇体积分数、液料比对提取液中玉米黄色素含量的影响,并研究了玉米黄色素在不同体系下的抗氧化活性。结果表明,玉米黄色素最佳提取工艺为:浸提温度70℃,浸提时间3 h,乙醇体积分数为80%,液料比10:1。玉米黄色素对DPPH·、超氧阴离子自由基以及羟基自由基均有清除作用,并且其对DPPH·和羟基自由基的清除效果优于BHT。当样品质量浓度小于9.0μg/mL时,玉米黄色素对超氧阴离子自由基的清除作用高于BHT。当样品质量浓度在9.0～15.0μg/mL范围内时,玉米黄色素对超氧阴离子自由基的清除作用与BHT基本一致。此外,玉米黄色素有较强的还原力,对三价铁离子的还原能力高于BHT。玉米黄色素能够抑制亚油酸过氧化,但其抗氧化作用低于BHT。     

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。     

微波法提取玉米黄色素的工艺研究

以玉米黄粉为原料,采用微波法提取玉米黄色素,研究结果表明,微波提取玉米黄色素的最佳工艺条件为:乙醇浓度为95%,原料目数80目,微波功率为640 W,微波时间为60 s,料液比1∶10,提取率为332.05μg/g。通过正交试验发现,影响提取效果的因素主次顺序为微波功率微波时间料液比。采用微波法提取玉米黄色素,可以有效地缩短提取时间,提高提取效率。     

超声波强化提取玉米黄色素工艺条件优化

以玉米皮为原料,利用超声波技术,以乙醇为提取剂从玉米皮中提取玉米黄色素,探讨了料液比、乙醇体积百分数、提取温度和提取时间对玉米黄色素提取率的影响。结果表明:最佳工艺条件为以乙醇作为提取剂,体积分数为60%,玉米皮与乙醇的料液比为1∶15,提取温度为50℃,超声波处理时间为30 min,乙醇提取率可达到6.274%。     

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。     

玉米黄色素提取工艺优化及其抗癌活性研究

探究超声辅助酶法制备玉米黄色素的最佳工艺,以及玉米黄色素对人胃腺癌细胞(BGC-823)生长的抑制作用。通过单因素和响应面试验,探讨超声辅助酶法制备玉米黄色素的最佳条件;用制备的玉米黄色素处理BGC-823细胞,并进行形态学观察和MTT法细胞存活率检测,初步考察其抗癌活性。超声辅助酶法提取玉米黄色素的最佳条件为:酶活力10 000U/g,超声功率400 W,酶解温度35℃,该条件下提取率达最大,为(72.64±0.42)μg/g;细胞形态学观察及MTT细胞活力检测显示玉米黄色素对BGC-823细胞具有一定的生长抑制作用。超声辅助酶法提取玉米黄色素是一种有效的提取方法,制备的玉米黄色素对BGC-823细胞生长有较强的抑制作用。     

起声波强化提取玉米黄色素工艺优化研究

以玉米蛋白粉为原料,乙醇、石油醚混合溶剂作为提取剂,采用超声波强化进行提取实验.采用二次旋转正交组合设计,探讨料液比、提取温度、混合溶剂中乙醇的体积百分数和提取时间对玉米黄色素提取率的影响.结果表明,最佳提取工艺条件为:液料比15:1,温度54℃,乙醇体积百分数47%,提取时间29min,玉米黄色素提取率为5.16%.本实验确定的提取方法使玉米黄色素的提取效率得到了显著提高,为工业化生产玉米黄色素提供了理论依据.     

响应面法优化微波辅助提取玉米醇溶蛋白工艺研究

玉米皮含有大量玉米黄色素和醇溶蛋白;该研究首先对玉米皮进行脱色处理得到玉米黄色素,然后利用微波辅助提取玉米醇溶蛋白,并在单因素试验基础上利用响应面法优化玉米醇溶蛋白提取工艺;结果表明,最佳提取工艺条件为:乙醇浓度75%、液料比12、微波功率450 W、间歇式微波处理5次,共225 s,提取率为73.6%。     

响应面法提取玉米醇溶蛋白的工艺优化

玉米皮中含有大量玉米黄色素和醇溶蛋白。本研究首先对玉米麸皮进行脱色处理得到玉米黄色素,然后在单因素试验的基础上,利用响应面分析法优化玉米醇溶蛋白提取工艺的最佳工艺条件。通过试验得到了二次多项式回归模型R2=0.989 6,该模型能较好的反映各因素与响应值之间的关系。最佳提取工艺条件是,添加液料比为9∶1(mL/g)的75%乙醇水溶液,60℃浸提2 h后,离心分离,提取液的吸光度值为0.014,醇溶蛋白一次提取率为71.49%。     

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