微波辅助法提取野生软枣猕猴桃茎黄酮的工艺优化

研究了微波辅助法提取野生软枣猕猴桃茎黄酮类化合物的工艺条件。通过单因素实验分别考察微波功率、提取时间、乙醇浓度、料液比对黄酮提取率的影响,以软枣猕猴桃茎黄酮的提取率为指标,根据单因素实验结果设计正交实验,得出微波辅助法提取的最佳工艺条件：微波功率为300W,乙醇浓度为70%,料液比为1∶32,提取时间为5min,此条件下软枣猕猴桃茎黄酮提取率为1.80%。     

微波萃取在菊花黄酮提取工艺中的应用研究

在微波单因素提取的基础上采取L9(34)正交优化试验,探讨乙醇浓度、微波提取时间和料液比对菊花黄酮提取率的影响.经过单因素试验及正交试验,结果表明:影响菊花黄酮微波提取的主要因素为乙醇浓度,其次为提取时间、料液比.在微波功率300 W的条件下,最佳提取工艺条件为乙醇浓度60%,提取时间120 s,料液比1∶20.此时总黄酮提取率为4.83%.     

微波辅助双水相提取菠萝皮中黄酮的研究

采用微波辅助乙醇-磷酸氢二钾双水相的方法对菠萝皮中黄酮进行提取,探讨了乙醇浓度、提取时间、微波功率、磷酸氢二钾用量和液料比等因素对黄酮提取的影响,并采用正交实验法进行优化。实验结果表明:最佳提取工艺为乙醇浓度为60％,提取时间为45 s,微波功率为464 W,液料比为40:1 (mL·g-1),在此条件下,黄酮得率可达5.34%。研究结果可为废弃资源的综合开发利用提供科学依据。     

微波法提取西南委陵菜黄酮及其抗氧化活性的细胞模型法评价

利用微波法以乙醇作为提取剂提取了西南委陵菜黄酮,考察了乙醇浓度、料液比、提取温度、微波功率和提取时间对西南委陵菜黄酮提取得率的影响。结果表明,微波法提取西南委陵菜黄酮的最佳条件是乙醇浓度50%、料液比1∶30、提取温度60℃、微波功率400W、提取时间5min。黄酮的最佳得率为5.68%。西南委陵菜黄酮在结肠癌细胞HT-29和小鼠巨噬细胞RAW264.7两种细胞中表现出明显的抗氧化活性,其抗氧化性随浓度增加递增。     

仙人掌黄酮微波法提取工艺响应面优化

仙人掌黄酮类化合物作为一种多酚类物质,具有广泛的生物活性和药理活性。随着食品及化妆品工业的发展与消费观念的改变,黄酮类化合物以纯天然、高活性、见效快、作用广泛等特点日益受到人们的关注。仙人掌黄酮的提取工艺以乙醇为溶剂采用微波法辅助提取。本实验首先分析微波功率、微波时间、乙醇浓度、液料比等单因素对黄酮得率的影响,随后用响应面软件对微波法提取仙人掌中黄酮提取工艺进行优化。结果表明:对于得率的影响程度为液料比提取功率乙醇浓度提取时间。利用响应曲面分析进行回归预测和优化后,仙人掌黄酮得率的最大预测值0.855%,此时的提取条件为:提取时间2.55min,液料比34∶1,乙醇浓度96.5%,超声功率310.6W。经过验证实验得到的提取率为0.832%,与预测值相差2.69%,在可接受范围内。     

响应面法优化微波辅助提取艾草黄酮工艺

以艾草为原料,通过单因素试验和响应面试验设计优化微波辅助提取黄酮工艺,分别考察了乙醇浓度、液料比、微波功率、微波时间对黄酮得率的影响。结果表明,最优工艺条件为:乙醇浓度72%、液料比45∶1(g/m L),微波功率520 W,微波时间151 s,在此工艺条件下,艾草黄酮得率为4.37%。     

微波技术在杜仲黄酮提取工艺中的应用研究

本文在微波单因素浸提的基础上,采取L9(34)正交优化试验,以探讨微波功率、乙醇浓度、料液比和提取时间对杜仲黄酮提取率的影响研究。单因素试验结果表明:最佳萃取工艺参数为,微波功率200W,乙醇浓度为50%,液料比为1:30,提取时间10min。正交试验结果表明:影响杜仲微波浸提的主要因素为乙醇浓度,其次是提取时间、料液比、微波功率。最佳提取工艺条件为为A2B3C2D3,即乙醇浓度50%,提取时间25min,料液比1:30,微波功率400W。此时总黄酮含量为0.7672%。     

响应曲面法优化千年健黄酮的提取工艺

单因素实验研究了微波时间、微波功率、乙醇浓度和液固比对千年健黄酮提取率的影响,利用响应面法对提取工艺进行优化,用Design-Expert 7.0软件对实验数据进行二次响应面分析。结果表明:各因素对黄酮提取率影响的次序为液固比微波功率乙醇浓度微波时间,最佳提取工艺条件为:微波功率273.8 W、微波时间5min、乙醇浓度50%、液固比30∶1(mL/g),在此条件下提取率为0.5881%。     

银杏愈伤组织黄酮提取条件的正交实验优化

以银杏愈伤组织为材料,对银杏黄酮的提取条件进行优化。通过单因素实验研究乙醇浓度、液料比、微波功率、微波时间、水浴温度、水浴时间等对黄酮得率的影响,并进行了正交实验优化。正交实验的结果表明:以40%乙醇为提取溶剂,液料比25∶1,在中火档(528W)微波60s,不进行水浴处理,黄酮得率达到20.92mg/g。     

三叶委陵菜黄酮的微波辅助提取工艺研究

研究三叶委陵菜中黄酮类物质的微波辅助提取工艺,采用微波辅助提取法提取了三叶委陵菜黄酮,考察乙醇浓度、微波功率、提取时间、回流温度、料液比对三叶委陵菜提取液中黄酮含量的影响,确定了微波萃取仪提取三叶委陵菜黄酮的最佳工艺条件为:以75%乙醇作溶剂,在料液比为1∶25(g/mL),温度70℃,功率400 W的条件下微波提取5 min,效果最好,提取液中总黄酮含量为4.24%。     

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