表面活性剂SDS辅助微波提取金佛手总黄酮工艺及抗氧化活性评价

通过单因素试验和正交试验设计,分别研究了表面活性剂十二烷基磺酸钠（sodium dodecyl sulfonate,SDS）质量分数、料液比、微波功率和微波时间对金佛手总黄酮提取量的影响。确定微波提取最佳工艺条件为表面活性剂SDS质量分数0.6%、料液比1∶20（g/mL）、微波功率50 W、微波时间30 s,在此工艺条件下金佛手总黄酮提取量为18.706 0 mg/g。金佛手总黄酮对DPPH自由基和ABTS自由基清除率分别为79.15%和65.25%,其抗氧化活性略低于槲皮素。结果表明,金佛手总黄酮具有显著抗氧化活性,可作为抗氧化剂应用到食品和医药领域。     

刀豆壳总黄酮提取工艺优化及其抗氧化活性研究

以刀豆壳的总黄酮提取量为评价指标,使用乙醇为提取剂,微波辅助提取刀豆壳总黄酮,分别考察乙醇体积分数(%)、液料比(mL/g)、微波时间(min)、微波功率(W)对刀豆壳总黄酮提取量的影响,通过响应面法优化提取工艺并研究提取的刀豆壳总黄酮的抗氧化活性。经试验得出当乙醇体积分数为50%,液料比为20:1(mL/g),微波时间为5.6 min,微波功率为600 W,总黄酮提取量为2.330 mg/g;刀豆壳总黄酮对羟自由基清除作用明显,其质量浓度与抗氧化活性有一定的量效关系。     

微波辅助提取山竹壳中的总黄酮及其体外抗氧化活性研究

采用微波辅助提取山竹壳中的总黄酮类化合物,测定其体外抗氧化活性。考察乙醇体积分数、液料比、微波功率、微波提取时间对总黄酮提取率的影响,并采用四因素四水平正交试验,确定总黄酮的最佳提取工艺条件。结果表明,最佳提取工艺为:乙醇体积分数75%,液料比35∶1(mL/g),微波功率300 W,微波提取时间3 min,此时总黄酮的提取率为12.02 mg/g。试验得出,该提取物对超氧阴离子自由基去除率最高达到72.34%、DPPH自由基去除率最高为68.52%,该提取物具有较好的体外抗氧化效果。     

微波法提取新疆罗布麻叶总黄酮及其抗氧化能力的研究

采用L9(34)正交试验对新疆罗布麻叶的微波提取工艺进行优选,以黄酮提取量为参考指标,确定最佳提取工艺条件为:1:12(g/mL)的80%乙醇水溶液,70%微波提取10min,提取4次,罗布麻叶提取总黄酮含量为56mg/g.研究了提取物的抗氧化能力,新疆罗布麻叶总黄酮对DPPH自由基有强的清除活性,IC50值为6.7ug/mL,抗氧化效果优于芦丁次于VC.     

枣叶黄酮微波-离子液体辅助提取工艺优化及其抗氧化活性研究

以枣叶为原料,枣叶黄酮提取率为指标,利用单因素分析结合正交试验的方法优化了枣叶黄酮的微波-离子液体辅助提取工艺条件,并研究了枣叶黄酮的抗氧化活性。结果表明:枣叶黄酮微波-离子液体辅助提取的最佳工艺条件为微波功率195 W、微波时间12 min,乙醇浓度60%、料液比1:25(g/mL)、离子液体1-辛基-3-甲基咪唑四氟硼酸盐的浓度为0.6 mol/L、提取次数2次。在该工艺条件下,黄酮提取率平均值为3.20%。抗氧化性研究显示,枣叶黄酮对DPPH自由基、羟自由基以及亚硝酸根离子均具有较强清除能力,IC_(50)分别为0.181 mg/mL、0.080 mg/mL和0.039 mg/mL,表明枣叶黄酮具有较强的抗氧化活性。     

柿叶黄酮超声辅助提取工艺及其抗氧化性研究

研究超声波辅助提取柿叶总黄酮的工艺条件及其抗氧化活性。采用单因素试验与正交试验,考察乙醇浓度、固液比、超声功率、浸提温度及提取时间等因素对柿叶总黄酮提取率的影响,并以柿叶总黄酮体外清除DPPH自由基能力为指标,评价其抗氧化活性。结果表明,超声波辅助提取柿叶总黄酮最佳工艺条件为乙醇浓度为70%,固液比1∶20(g/mL),超声功率350 W,超声时间40 min,浸提温度55℃,提取2次,柿叶总黄酮得率约为0.70%(以干柿叶计);在0~100μg/mL范围内,柿叶总黄酮抗氧化能力高于VC,对DPPH自由基的体外清除率达85.96%;超过100μg/mL时,清除作用基本稳定不变,浓度和清除率不显示量效关系。通过拟合线性方程计算柿叶总黄酮的IC_(50)值为5.45μg/mL,表明柿叶黄酮是良好的抗氧化剂。     

咪唑类离子液体提取沙棘叶总黄酮的研究

合成了6种咪唑类离子液体,并将其用于沙棘叶总黄酮的提取。以沙棘叶总黄酮提取率为指标,考察了微波时间、微波功率、微波温度、料液比、离子液体浓度对提取率的影响,利用单因素分析方法结合正交试验优化了沙棘叶总黄酮的提取工艺,并研究了沙棘叶总黄酮的抗氧化活性。结果表明:沙棘叶总黄酮的最佳提取条件为:1.0mol·L~(-1)溴化1-十二烷基-3-甲基咪唑的60%乙醇溶液作为提取剂,微波功率500W、微波温度80℃、微波提取时间6min、料液比1∶20(g·mL~(-1))。在该提取工艺下,沙棘总黄酮提取率为10.63%。抗氧化活性研究显示,该方法提取的沙棘叶总黄酮对DPPH自由基有较好的清除能力,IC_(50)为0.0511mg·mL~(-1)。     

响应面优化罗汉松总黄酮提取工艺及其抗氧化性研究

研究了罗汉松总黄酮提取工艺及其抗氧化活性。在单因素试验基础上,采用响应面法对乙醇浓度、液料比、超声功率、提取时间4个因素进行优化,得到罗汉松总黄酮的最佳提取工艺:乙醇浓度73.5%、液料比49∶1(mL/g)、超声功率500 W、提取时间40min,在该条件下罗汉松总黄酮的提取率达到6.271%。体外抗氧化性研究表明,罗汉松总黄酮对DPPH自由基、羟自由基、超氧阴离子的IC50分别为0.369、0.487、0.520 mg/mL,其对3种自由基的清除能力虽然弱于维生素C,但仍表现出较好的抗氧化活性。     

福白菊总黄酮的微波辅助提取工艺优化及其抗氧化活性研究

以麻城福白菊为原料,利用单因素试验及响应面试验设计优化微波辅助提取总黄酮工艺,并评价提取物的抗氧化活性。结果表明,福白菊总黄酮的最佳提取工艺为：料液比1:40（g:mL）,微波提取时间60 s,微波功率400 W。此优化条件下,总黄酮得率为7.31%。抗氧化试验结果表明,当总黄酮类提取物质量浓度为0.010 g/L时,还原力为0.099,其总抗氧化能力最强;当其质量浓度为0.50 g/L时,清除1,1-二苯基-2-三硝基苯肼（DPPH）自由基的能力最强,为77%。     

牛油果黄酮提取工艺优化及其体外抗氧化活性分析

为明确牛油果中总黄酮最佳提取工艺,并确定其抗氧化活性,利用微波辅助响应面法优化牛油果总黄酮提取工艺,并以提取的总黄酮进行DPPH~.、羟自由基和还原力的抗氧化性试验。结果表明:经过响应面优化,得到最佳工艺参数,修正后为料液比为32 mL/g、乙醇浓度72%、微波功率为268 W和提取时间28 min,取得的提取率为19.68 mg/g,与理论值(19.77 mg/g)相差为0.46%;牛油果总黄酮体外抗氧化活性实验表明,相同浓度下其对2种自由基清除能力优于BHT,弱于Vc,且具有较强的还原能力。研究结果可以为牛油果黄酮提取和抗氧化应用提供理论指导。     

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