茜草总黄酮提取工艺研究

研究茜草总黄酮的提取工艺条件。采用热浸提法提取茜草总黄酮,硝酸铝显色法测定总黄酮提取率。通过单因素试验研究乙醇体积分数、料液比、提取温度、提取时间对黄酮提取率的影响,通过正交试验进一步优化提取工艺条件。单因素试验结果显示,乙醇体积分数50%、提取温度70℃、提取时间2.5h、料液比1:40(g/mL)条件下茜草总黄酮提取率较高;正交试验结果表明:茜草总黄酮的最佳提取工艺为60%、乙醇溶液提取2h、提取温度70℃、料液比1:40(g/mL),此条件下茜草总黄酮提取率为1.67%。本工艺简单可行,有较好的参考价值。     

月见草叶中总黄酮提取工艺条件研究

目的:研究月见草叶中的有效成分总黄酮的最佳提取条件。方法:采用乙醇浓度(%)、提取时间(h)、料液比(g/mL)作为研究因素,以提取液中总黄酮的含量为考察指标,通过正交试验,得到从月见草叶中提取总黄酮最佳工艺条件。结果:月见草叶中提取总黄酮最佳工艺条件为乙醇浓度80%、提取时间2h、料液比1∶30。影响总黄酮提取的主要因素是乙醇浓度(%),其次是提取时间(h),料液比(g/mL)影响最小。结论:本试验采用溶剂提取法提取月见草叶中的总黄酮,此方法操作简单,并且可节约成本;采用正交试验法优选提取工艺,该方法可减少试验次数、减少时间和费用,方便、准确、值得推广。     

正交试验法优化超声提取使君子叶总黄酮

采用正交试验法优化超声辅助提取使君子叶总黄酮的工艺条件。以总黄酮得率为指标,考察乙醇浓度、料液比、提取时间对使君子叶总黄酮提取率的影响,利用正交试验法优化最佳提取工艺条件。结果表明,影响使君子叶中总黄酮超声辅助提取效果的主次因素为:料液比乙醇浓度超声时间。最佳提取条件为料液比为1:30,乙醇浓度60%,超声时间40 min。在该条件下,君子叶中的总黄酮的得率为5.47%。     

超声波提取菟丝子总黄酮的工艺研究

在超声波单因素提取的基础上,采取L16(45)正交优化试验,探讨乙醇浓度、提取时间、提取温度和料液比对菟丝子总黄酮提取工艺的影响,结果表明影响菟丝子黄酮超声提取的主要因素为乙醇浓度,其次为提取时间、提取温度和料液比.最佳提取工艺条件为:乙醇浓度70%,料液比1:30,提取温度40℃、提取时间40 min.在该条件下测得菟丝子总黄酮的含量为3.46%.     

艾蒿总黄酮的超声波提取工艺研究

为了确定艾蒿叶、茎中黄酮的超声波提取工艺,以黄酮得率为考察指标,比较了不同溶剂对艾蒿叶、茎中黄酮的提取效果,并采用正交试验,研究了提取溶剂浓度、提取时间和料液比对黄酮提取得率的影响。确定了艾蒿叶中黄酮最佳提取工艺条件为:乙醇浓度为60%,料液比为1∶40(g/mL),提取时间60 min;在此条件下,艾蒿叶总黄酮提取得率为9.71%。艾蒿茎中黄酮最佳提取工艺条件为:50%乙醇,料液比1∶20(g/mL),超声提取60 min;在此条件下,艾蒿茎总黄酮提取得率为1.65%。     

杜仲叶总黄酮的超声提取工艺

利用超声法对杜仲叶中总黄酮的提取工艺进行研究。单因素考察超声功率、超声时间、乙醇浓度、料液比、提取次数等因素对总黄酮得率的影响,并用正交试验对总黄酮的提取工艺条件进行优化。结果表明,杜仲叶总黄酮最佳提取工艺条件为:超声功率600 W,超声时间30 min,乙醇浓度60%,料液比1∶15(g/mL),提取2次,在最佳条件下总黄酮得率为2.04%。     

超声波辅助提取菊花总黄酮的工艺研究

用超声波提取技术提取菊花中黄酮,在单因素提取基础上,采取正交优化试验,探讨乙醇浓度、料液比、提取温度和提取时间对菊花总黄酮提取工艺的影响,结果表明,影响菊花黄酮超声提取的主要因素为乙醇浓度,其次为提取时间、提取温度和料液比.最佳提取工艺条件为乙醇浓度60%,料液比1:40,提取温度40%℃,提取时间50min,测得菊花总黄酮为3.97%.     

响应曲面法优化黄秋葵花总黄酮的提取工艺

为提高黄秋葵花总黄酮的提取率,利用响应曲面法优化了黄秋葵花总黄酮的回流提取工艺。在乙醇浓度、提取温度、料液比、提取时间共4个单因素试验的基础上,采用Box-Behnken design方法进行四因素三水平试验,以总黄酮提取率为响应值,通过响应面分析得到二次多项式回归方程的预测模型。结果表明:料夜比对黄秋葵花总黄酮提取率的影响达到极显著水平(P0.01),乙醇浓度与提取温度对提取率的影响达到显著水平(P0.05),四因素对总黄酮提取率的影响作用大小依次为:料液比提取温度乙醇浓度提取时间。黄秋葵花总黄酮提取的最佳工艺条件为乙醇浓度40%,提取温度60℃,料液比1∶160(g∶mL),提取时间30min。黄秋葵花总黄酮提取率预测值为28.72mg/g,验证后提取率为27.98mg/g,与预测值基本吻合,相对误差为2.58%。     

响应曲面法优化微波提取小茴香总黄酮工艺研究

为优化小茴香总黄酮的微波提取法,应用Design-Expert 8.0.5b软件的Box-Behnken响应面分析方案设计试验。结果表明:乙醇浓度、提取温度、液料比对小茴香总黄酮提取率的影响极显著,提取时间和液料比的交互作用、提取温度和液料比的交互作用的影响也达到显著水平,小茴香总黄酮提取的最佳工艺条件为乙醇浓度56%、提取时间11min、提取温度62℃、液料比39(mL/g),在此条件下,小茴香总黄酮的提取率为1.3453%。     

超声波辅助提取大球盖菇总黄酮工艺优化

主要研究了超声波辅助提取大球盖菇中总黄酮的提取工艺,研究了乙醇浓度、超声功率、时间、料液比对大球盖菇总黄酮提取率的影响。通过单因素试验和正交试验确定了大球盖菇黄酮类化合物的优化提取工艺条件。超声波优化提取工艺条件为:乙醇浓度30%,料液比1∶15(g/m L),超声功率120 W,时间1 h,总黄酮的提取率为1.138%。     

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