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%.     

枣核总黄酮的微波辅助提取工艺优化

目的：采用正交试验法,优选枣核中总黄酮的微波辅助提取工艺。方法：以芦丁为对照品,采用分光光度法进行测定,以枣核黄酮提取率作为考查指标,对影响黄酮提取工艺的因素进行研究。通过单因素试验研究微波功率、提取时间、提取温度、料液比和提取溶剂乙醇体积分数对提取效果的影响。然后,利用正交试验法优化最佳提取工艺条件。结果：对枣核黄酮提取的影响程度大小顺序为料液比＞提取温度＞提取时间＞乙醇体积分数＞微波功率,正交试验结果表明最佳提取工艺参数为料液比1:60(g/mL)、提取温度60℃、乙醇体积分数50%、提取时间20min、微波功率500W。在最佳工艺条件下,枣核黄酮粗品的提取产率为10.14%,粗品中黄酮含量为7.00%。结论：采用正交试验-微波提取工艺,能显著提高枣核黄酮的提取效率,具有较好的提取效果。     

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%。     

微波提取红花黄酮类化合物的研究

对红花黄酮类物质的微波提取工艺进行了探讨。采用单因素试验与正交试验,分别考察了乙醇浓度、微波时间、微波功率、微波温度及料液比对红花黄酮类化合物提取率的影响。试验结果表明,最佳的提取条件为乙醇浓度60%vol,料液比1∶35,微波功率800W,提取时间25min,提取温度50℃,提取2次。在此条件下,红花黄酮的提取率达到10.23%。     

车前草总酚的微波提取

为优化得到车前草中总酚的最佳微波提取工艺条件,通过单因素和正交试验进行筛选。结果表明:影响车前草总酚提取率的主要因素顺序为,微波处理时间>乙醇浓度>料液比>微波功率;车前草总酚的最佳提取工艺为,60%乙醇、料液比1∶15(g∶mL)、微波处理3 min、微波功率为450 W。在此条件下车前草总酚的提取率最高,为3.61%。该法对车前草总酚提取率高,且缩短提取时间,节约能源。     

微波提取藏茵陈总黄酮的工艺

本文用微波提取法提取出了藏茵陈中总黄酮,通过化学方法对藏茵陈中总黄酮进行了定性鉴定,设计了正交试验考察影响总黄酮提取率的4个因素,设计单因子试验确定了这四大因素的最佳提取条件。结果表明：藏茵陈提取液中含有黄酮类化合物;微波提取藏茵陈中总黄酮的4个因素对提取效果影响的次序为乙醇浓度〉微波功率〉微波提取时间〉料液比,最佳的提取工艺为料液比1∶35,乙醇浓度70%,微波功率700W,微波提取时间8min,该工艺条件下总黄酮提取率达5.56%     

微波辅助提取苦菜总黄酮的工艺优化

用微波辅助提取技术提取苦菜总黄酮,用亚硝酸钠-硝酸铝比色法测定黄酮含量。微波辅助提取苦菜总黄酮工艺进行研究。通过单因素和正交试验,探讨了不同因素对乙醇提取苦菜黄酮提取率的影响,确定了最佳的工艺参数。结果表明:各因素对微波辅助提取苦菜黄酮提取率的影响程度由大到小为提取时间>料液比>乙醇浓度;确定了微波处理苦菜总黄酮的最佳方案为A1B3C1,即乙醇浓度40%,时间8 min,料液比1:30。在此条件下,微波处理后苦菜黄酮得率可达19.6 mg/g。     

苦丁茶总黄酮提取工艺优化研究

利用微波辅助提取苦丁茶总黄酮,并对提取条件进行优化。以苦丁茶粉为原料,探讨乙醇浓度、料液比、提取时间、提取温度对总黄酮提取的影响。在单因素试验基础上,对乙醇浓度、料液比、提取时间、提取温度4个因素进行正交试验,以总黄酮提取率为指标对提取条件进行优化。在乙醇浓度50%、料液比1∶20(g/mL)、提取温度80℃、提取时间8 min,总黄酮提取率达到7.630 mg/g。优化后的总黄酮提取率比单因素试验有较大提高。     

微波提取低温豆粕中大豆皂甙

采用微波法提取低温豆粕中的大豆皂甙,通过单因素实验和正交实验研究了微波火力、乙醇浓度、料液比、微波时间对大豆皂甙提取率的影响.结果表明,在试验条件范围内各因素对大豆皂甙提取率影响的主次顺序为:微波时间＞微波火力＞乙醇浓度＞料液比;在微波火力为中高火、微波时间为2.5 min、乙醇浓度为60％、料液比为1:25 (g/mL)的条件下得到最优工艺条件,此条件下大豆皂甙的提取率为0.634％.     

金桂花中总黄酮的微波辅助提取工艺优化

以金桂花为原料,综合运用单因素和正交试验设计,考察乙醇体积分数、料液比、微波功率和提取时间对黄酮类化合物提取率的影响。结果表明:影响微波辅助提取金桂花中总黄酮提取率的因素主次为提取时间料液比乙醇浓度微波功率,其最佳提取条件为:乙醇浓度50%,料液比1︰35(m︰V),提取时间8×20s(提取8次,每次20s,每次时间间隔2min)、微波功率300 W,该条件下,金桂花中总黄酮的提取率达20.30%。     

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