超临界CO2萃取花椒果皮总黄酮的工艺

以七年生花椒果皮为原料,进行超临界CO2萃取分离花椒总黄酮的工艺研究,采用硝酸铝-亚硝酸钠法对萃取物中的总黄酮含量进行了定量测定,重点考察了萃取温度、萃取压力、萃取时间以及夹带剂用量对总黄酮得率的影响.正交实验结果表明,各种因素对花椒萃取率的影响的程度从高到低依次为:萃取温度＞萃取压力＞萃取时间＞夹带剂用量.超临界CO2流体萃取花椒黄酮的优化条件为:萃取温度为50℃,萃取压力35MPa,萃取时间150min,夹带剂用量4mL/g,此时花椒总黄酮提取率为19.574％.     

超临界CO2萃取竹叶中总黄酮的研究

采用超临界CO2萃取技术,在CO2流量为25L／h的条件下,对影响竹叶中总黄酮提取率的4个因素（温度、时间、压力和夹带剂用量）进行了研究。运用正交试验得出了最佳的萃取工艺条件为温度为40℃,时间为3h,压力为30MPa,夹带剂用量为4．5mL／g。     

超临界CO2萃取大蒜油的工艺研究

本文研究了影响超临界流体萃取（SFE）技术对大蒜油提取的相关因素，包括萃取压力、萃取温度、萃取时间、夹带剂用量等。通过正交试验，确定了超临界CO2萃取大蒜油的适宜工艺参数组合：以15％（V／W）无水乙醇为夹带剂，萃取压力为25MPa，萃取温度为40℃，萃取时间为240rain，在上述提取条件下，SFE提取的大蒜油得率达到0．446％。结果表明：超临界流体萃取的大蒜油呈淡黄褐色，半透明状，略有流动性，呈新鲜大蒜风味。     

超临界CO2萃取杜仲叶总黄酮的研究

本论文采用超临界CO2萃取技术萃取杜仲叶总黄酮,对萃取温度、时间、压力和夹带剂用量四因素进行研究,并采用紫外分光光度法对萃取物中的总黄酮进行定量分析。确定了超临界CO2萃取杜仲总黄酮的最佳工艺条件为:温度为45℃、时间为2.5h、压力为30MPa、夹带剂用量为3.5ml/g。黄酮提取率为73.26%,产品纯度为19.82%。     

超临界CO_2流体萃取洋葱油的工艺研究

进行超临界CO2萃取洋葱油的试验研究,探讨萃取压力、萃取温度、萃取时间以及夹带剂用量等对洋葱油得率的影响,并通过正交试验确定了超临界CO2技术萃取洋葱油的最佳工艺参数.结果表明,影响洋葱油得率主要因素的依次顺序为萃取压力>夹带剂用量>萃取温度>萃取时间.萃取压力20MPa,加入无水乙醇15%为夹带剂,萃取温度40℃,萃取时间240min,洋葱油得率可达到0.492%.     

超临界CO_2法萃取芹菜叶黄酮

在考察超临界CO2萃取温度、萃取压力、萃取时间以及夹带剂用量等单因素对黄酮萃取率影响的基础上,采用Box-Behnken响应曲面设计法,建立影响因素和黄酮得率之间的回归方程。结果表明:萃取温度、萃取压力、萃取时间对超临界CO2萃取芹菜中黄酮工艺影响极显著,夹带剂用量影响显著,最佳提取工艺条件为萃取温度70℃、萃取压力30 MPa、萃取时间2.5 h、夹带剂用量为1 mL/g。该条件下黄酮得率为9.03%,与预测值相近,差异不显著,符合实验要求。     

超临界CO_2萃取长裙竹荪总黄酮的工艺优化及抗氧化研究

通过单因素实验探讨了萃取温度、CO2流量、萃取压力、萃取时间、夹带剂用量、分离试剂种类及用量对长裙竹荪总黄酮得率的影响,并采用响应面分析法确定超临界CO2萃取长裙竹荪总黄酮的最佳工艺条件为:萃取温度40℃,CO2流量10L/h,萃取压力35.5MPa,萃取时间122min。在此条件下,添加2∶1(V∶m)的95%乙醇作为夹带剂,以1∶4(V∶V)的石油醚对粗提物进行分离纯化,得到的长裙竹荪总黄酮得率可达3.6mg/g。抗氧化实验表明,长裙竹荪提取物有很好的还原性,对超氧阴离子(O2-·)、DPPH·和羟基自由基都有较好的清除能力,具有良好的抗氧化性。     

超临界CO2萃取桑枝黄酮工艺的研究

以桑枝为研究对象,采用超临界CO₂萃取技术,以桑枝总黄酮得率为指标,通过单因素试验和正交试验考察了萃取温度、萃取时间、萃取压力和夹带剂流速对桑枝总黄酮得率的影响,优化超临界CO₂萃取桑枝黄酮工艺。结果表明,在萃取温度40℃、萃取时间45 min、萃取压力45 MPa以及夹带剂流速0.750 mL·min^-1的条件下,桑枝总黄酮得率为2.481 7 mg·g^-1,其中夹带剂流速对桑枝总黄酮得率的影响最为显著,萃取压力次之,萃取温度和萃取时间的影响相对较小。     

大叶白麻中总黄酮超临界CO_2萃取工艺优化

采用超临界CO2流体萃取技术提取大叶白麻叶中的总黄酮,并对其提取工艺进行优化。通过正交试验研究夹带剂用量、萃取压力、萃取温度及萃取时间4个因素对总黄酮提取率的影响。结果表明,大叶白麻总黄酮最佳提取工艺为:原料大叶白麻150g,夹带剂为900mL 70%乙醇(pH=10),萃取温度45℃,萃取压力20 MPa,萃取时间2h。该工艺条件下,大叶白麻中总黄酮的提取率为5.28%,高于溶剂提取法的提取率。     

超临界CO2萃取桂花油的工艺研究

研究了用超临界CO2萃取方法提取桂花油的工艺条件，考察了萃取时间、温度、压力、夹带剂对桂花油收率的影响，并且借助气相色谱考察了采用不同夹带剂时所得桂花油成分的变化。结果表明，桂花萃取最佳工艺条件为：压力15MPa温度50℃，时间20min，采用水-乙醇混合夹带剂（含水40％）下桂花油的提取收率最高，收率可达1.07％，此时萃取了桂花中所含的各种极性的成分。     

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