微波辅助提取苦参总黄酮

研究苦参中黄酮类化合物的微波提取最佳工艺。采用单因子及正交实验，考察了乙醇浓度、微波时间、微波功率及固液比对苦参黄酮类化合物提取量的影响规律。结果：苦参黄酮类化合物提取工艺的最佳参数组合为：乙醇体积分数10％，微波作用时间6min，功率为420w，固液比为1：25（g／mL）。在最佳参数组合下苦参中总黄酮的提取量可达4．83％。结论：采用微波技术提取苦参中总黄酮具有良好的应用前景。     

苦参中黄酮类组分的提取及抗氧化性的研究

用正交试验探索超临界萃取苦参中黄酮类组分的最佳工艺条件,最佳参数为:温度40℃,压力30 MPa,乙醇流速0.4 mL/min,时间60 min,最高得率为5.82%.在此基础上对苦参中黄酮类组分进行分离提取,用分光光度法测定其抗氧化性.结果显示苦参中黄酮类组分对自由基有消除作用.     

超声波辅助法提取山黄皮果仁中的总黄酮

目的:确定山黄皮果仁中总黄酮最佳提取工艺。方法:采用超声波辅助法提取山黄皮果仁中的黄酮类化合物,通过单因素实验和正交实验,考察超声波提取条件(乙醇浓度、料液比、超声波功率、提取温度及超声波提取时间)对山黄皮果仁总黄酮提取率的影响。结果:山黄皮果仁总黄酮提取最佳工艺为:温度50℃,60%乙醇,料液比1:35,超声功率70 W,提取时间30 min。结论:在此工艺条件下提取,总黄酮提取率为1.159%。     

大果沙枣果肉中总黄酮的提取工艺研究

为研究大果沙枣果肉中总黄酮的最佳提取工艺,采用超声辅助提取法,以乙醇为溶剂,总黄酮提取率为考察指标,通过单因素试验和正交试验研究乙醇浓度,提取时间,提取次数和提取温度对总黄酮提取率的影响。结果表明,影响大果沙枣果肉中总黄酮提取率的主要因素是提取温度,其次是乙醇浓度、提取次数和提取时间。最佳提取工艺为:乙醇浓度40%vol,时间30min,提取次数3次,提取温度70℃。并在该条件下测得大果沙枣果肉中黄酮类化合物的含量分别为0.643%。     

超声波辅助法提取苹果渣中总黄酮的研究

研究利用超声波提取苹果渣中黄酮类化合物的工艺.通过单因素试验考察乙醇浓度、超声渡功率、提取温度、处理时间、料液比和浸泡时间对总黄酮提取率的影响.在单因素试验的基础上,利用正交试验确定超声波法提取苹果渣中总黄酮类化合物的最佳工艺条件:80%乙醇,超声波作用时间30 min,超声波功率480W,液料比1:40(g/mL),浸泡时间24h,超声波温度70℃,提取2次,总黄酮提取率为7.42mg/g.     

表面活性剂协同超声波提取合欢花中黄酮类化合物

采用超声波协同表面活性剂法提取合欢花中黄酮类化合物,以总黄酮提取率为指标,考察表面活性剂种类及浓度、固液比、提取温度、超声时间对提取合欢花中黄酮类化合物的影响,并经正交试验进一步优化工艺参数。结果表明:最佳工艺条件为表面活性剂选择0.8%十二苯磺酸钠(SDBS),固液比1∶40(g∶m L),提取温度40℃,超声时间30min。与其他提取方法相比,SDBS具有很好的协同作用,具有节能省时、提取率高等优点,最佳提取率为2.55(n=3,RSD=1.61%)。     

槲寄生中黄酮类化合物不同提取工艺的研究

采用超临界C02萃取、回流提取、超声波辅助浸提三种方法提取槲寄生中的黄酮类化合物。结果表明，超声波辅助浸提法总黄酮提取率优于超临界C02萃取法和传统的溶剂回流提取。通过正交试验，得到最佳工艺条件为乙醇体积分数80％，超声时间15rain，溶剂用量40ml／g，此条件下总黄酮的提取率为1．37％。     

梓树果实中黄酮类化合物提取工艺研究

以梓树果实为原料,对黄酮类化合物提取工艺进行研究,采用单因素试验法对影响梓树果实中黄酮类化合物提取率的主要因素进行了分析,利用正交试验优化了提取总黄酮的最佳工艺条件.研究表明,梓树果实中提取黄酮类化合物的最佳条件为:乙醇浓度60%,提取温度70"C,料液比1:20,提取时间2.Oh,在最佳条件下总黄酮的提取率为4.83%.     

八角和八角残渣总黄酮提取工艺优化

目的：确定八角和八角残渣中总黄酮的最佳提取工艺。方法：采用乙醇热回流法提取八角和八角残渣中的黄酮类化合物,通过单因素试验和正交试验,考察乙醇体积分数、料液比、提取时间、提取次数对八角和八角残渣中总黄酮提取率的影响。结果：八角总黄酮提取最佳条件为：80% 乙醇、料液比1:30、提取时间120min、提取次数3 次。八角残渣总黄酮最佳提取条件为：乙醇体积分数50%、料液比为1:10、提取时间120min、提取次数3 次。结论：在最佳工艺条件下,八角总黄酮提取率为23.61%,八角残渣总黄酮提取率为16.81%。     

超高压提取葡萄籽总黄酮的研究

利用超高压技术提取葡萄籽中黄酮类化合物。在单因素实验的基础上,采用正交实验法对葡萄籽中黄酮类化合物的超高压提取工艺进行优化,以总黄酮的提取率为指标,用分光光度法测定其含量。得到最佳工艺条件为:乙醇体积分数75%、提取压力325MPa、保压时间6min、提取温度50℃、料液比1:35(g/mL),优选结果经验证实验,获得较高得率为7.29%。     

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