响应面法优化超声波-微波协同提取富硒蛹虫草硒多糖工艺

在单因素试验基础上,采用响应面法对富硒蛹虫草硒多糖超声波-微波协同提取工艺进行优化,并与超声波提取法和水提法提取硒多糖抗氧化活性进行比较分析,探究3 种提取方法对硒多糖提取效果的影响。结果表明：超声波-微波协同提取最佳工艺条件为超声时间26.0 min、微波时间3.20 min、微波功率350 W、液料比32.00∶1（mL/g）,在此条件下,硒多糖提取率为5.05%,比超声提取法和水提法分别提高了19.96%和3.70%;3 种提取方法硒多糖体外抗氧化活性排序依次为：超声波-微波协同提取法＞超声波提取法＞水提法。此外,超声波-微波协同提取法可获得更高的多糖硒含量,为360.37 mg/kg,相比超声提取法和水提法分别提高了4.47%和12.92%。     

菊花中黄酮类物质提取方法的研究

就水提法、醇提法、超声波法对菊花中黄酮类化合物的提取效果进行了比较,并使用正交实验确定了最佳提取条件。实验结果表明,菊花中总黄酮类物质的醇提法最佳提取条件为C3B3A1,即用1倍量80%的乙醇连续回流提取3次(每次2h);超声波法的最佳提取条件为:将样品置于60倍样品重的80%乙醇中浸泡24h,超声波提取15min。     

不同方法提取甜荞麦麸皮总黄酮研究

为提高荞麦麸皮利用率,采用乙醇浸提法、超声波辅助提取法和微波加热提取法对提取甜荞麦麸皮黄酮类化合物工艺进行研究。实验结果表明,乙醇浸提法最佳工艺条件为:用50倍50%乙醇在70℃水浴中浸提2.5 h,浸提三次,总黄酮得率为2.4195%;超声波辅助提取法最佳工艺条件为:用60倍70%乙醇在70℃下超声波30 min,超声波提取三次,总黄酮得率为2.8953%;微波加热提取法最佳工艺条件为:用40倍50%乙醇在360 W功率下加热90 s,提取两次,总黄酮得率为2.7963%。比较三种方法结果,以超声波辅助提取法较优,更适于工业化生产。     

紫甘蓝色素提取方法研究

采用传统水浴提取法、超声波辅助提取法和微波萃取法对紫甘蓝天然色素的提取工艺条件进行研究。得到各方法的较优化提取条件：传统水浴提取法最佳工艺条件为25%乙醇溶液为溶剂、pH2、55℃水浴浸提4h;超声波辅助提取法最佳工艺条件为25%乙醇为溶剂、pH2、55℃水浴、超声波辅助浸提45min;微波萃取法最佳工艺条件为25%乙醇为溶剂、pH2、55℃水浴、微波功率300W、微波萃取时间3min。后两种方法的提取效果基本一致并优于传统水浴提取法,提高了生产效率。该色素具有良好的应用前景。     

水提紫甘薯色素废渣总黄酮提取工艺研究

目的研究水提紫甘薯色素废渣总黄酮的提取工艺,旨在为紫甘薯废渣的综合开发利用提供理论基础和参考依据。方法采用溶液浸提法、超声波辅助法、微波萃取法对水提紫甘薯色素废渣中的总黄酮进行提取研究,通过单因素实验和正交实验确定最佳提取方法及工艺条件。结果水提紫甘薯色素废渣总黄酮最佳提取方法为微波萃取法,其最佳提取工艺:乙醇体积分数70%,提取时间4 min,微波功率708 W,料液比1:40。在此条件下累计6次提取结果得水提紫甘薯色素废渣中总黄酮含量为3.83 g±0.03 g/100 g。最佳提取次数为2次。结论水提紫甘薯色素废渣黄酮类物质含量较高,具有较大的开发利用价值。     

黄酮类化合物提取工艺研究

综述了天然黄酮类物质的9种提取工艺，分别是水提法，碱性水或碱性稀醇提取法，有机溶剂提取法，微波法，超声波法，酶解法，大孔树脂吸附法，超滤法，超临界萃取法。     

苦荞黄酮提取方法的研究及含量测定分析

以贵州苦荞为研究对象,对超声波辅助醇提法、微波辅助醇提法2种方法提取苦荞麦中的黄酮类化合物进行了比较分析,并对2种方法总黄酮和芸香苷含量的精密度、重现性和回收率进行了验证。结果表明:超声波辅助醇提法的最优工艺条件为乙醇质量分数70%、料液比1∶30、提取时间30min、提取温度40℃,总黄酮得率为2.35%,芸香苷含量为1.141%;微波辅助醇提法的最佳工艺条件为乙醇质量分数60%、提取时间1min、料液比1∶40,总黄酮得率为2.47%,芸香苷含量为1.193%。2种提取方法相比,微波提取效果优于超声提取,差异显著(p0.05),微波辅助醇提法大大节省了时间。     

花生茎中白藜芦醇提取方法的研究

对溶剂浸提法、超声波提取法以及微波提取法提取花生茎白藜芦醇的工艺进行了研究。采用单因素结合正交试验的方法优化了白藜芦醇的提取条件。结果表明,最佳提取方法为超声波提取法,提取条件为：乙醇浓度80%、料液比1∶10、提取时间20min,提取率为0.11%。     

丝光绿蝇幼虫油脂提取方法的响应曲面优化

为确定丝光绿蝇幼虫油脂的提取方法和性质,为其利用奠定基础,以石油醚为溶剂,采用浸提法和超声波协同微波提取法提取丝光绿蝇幼虫油脂,用响应曲面对2种方法进行优化,得出最佳提取条件,并对油脂的理化性质进行了分析。得到浸提法的最佳提取条件为:温度40℃,时间7.93h,料液比1∶19.71,理论得率28.27%,实际得率为27.89%;得到超声波协同微波提取法的最佳提取条件为:时间10 min,料液比1∶12,超声波功率339.10 W,微波功率446.64 W,温度57.77℃,理论得率24.69%,实际得率为24.67%。2种方法提取油脂的碘值相近,超声波协同微波提取法油脂的酸值(KOH)较低,为6.55 mg/g;浸提法油脂的过氧化值为6.22 meq/kg;2种油脂颜色饱和值S分别为0.72、0.95,超声波协同微波提取法油脂颜色较深。浸提法提取油脂得率较高,超声波协同微波提取法耗时最短,品质较好。综合分析,超声波协同微波提取法是丝光绿蝇幼虫油脂的适宜提取方法。     

库拉索芦荟中芦荟多糖提取方法的比较

对库拉索芦荟中芦荟多糖的3种常用提取方法的提取条件分别进行研究,得到热水浸提法、微波辅助法和超声波辅助法的最佳提取条件,并分别在最佳提取条件下比较了3种方法对芦荟多糖提取率的影响。结果表明,超声波辅助法最有利于库拉索芦荟中芦荟多糖的提取,超声波辅助法的最佳提取条件为超声波功率800 W,超声波时间9 min,料液比为1∶30(g/mL),芦荟多糖的提取率为5.42%。超声波辅助法芦荟多糖的提取率分别比热水浸提法和微波辅助法提高了4.43%和3.83%。     

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