菊花速溶茶的制备工艺和质量标准研究

研究了菊花速溶茶的制备工艺和质量标准.本文采用正交实验的方法研究了菊花超声提取的工艺.以及采用正交实验的方法优化了菊花速溶茶喷雾干燥的工艺,并采用薄层和高效液相的方法对菊花速溶茶的主要成分绿原酸进行了定性和定量鉴别;确定了菊花超声提取的最佳工艺为:用10倍水提取3次,每次提取时间为1.0h;优化的喷雾干燥工艺条件为:进口温度为200℃,喷雾压力为180kPa,料液相对密度为1.05;在TLC图谱中可检出菊花的特征斑点,绿原酸在0.984～5.241～g间线性关系良好(r=0.9999),加样回收率为98.80%(RSD=1.08%).     

超声波辅助乙醇法萃取金银花中绿原酸

为了提高金银花中绿原酸的提取率,在研究提取温度、乙醇浓度、提取时间和配料比等单因素对金银花中的绿原酸提取影响的基础上,运用正交试验优化了金银花中绿原酸的醇提工艺,研究发现:用70%乙醇为萃取剂,在60℃和1∶15配料比的条件下,提取15 min时,提取率最高,为1.353%。     

微波辅助提取金银花中绿原酸及其清除自由基活性初步研究

目的筛选微波辅助提取金银花中绿原酸的最佳工艺;初步探讨绿原酸清除自由基的活性。方法以金银花中绿原酸含量为考察指标,考查提取溶剂浓度、料液比、提取时间、微波功率等因素对提取效果的影响。采用正交试验设计优化了最佳提取工艺,采用DPPH法测定不同物质对总自由基的清除作用。结果最佳提取条件为:乙醇浓度55%,料液比1:40,提取时间2min,微波功率520W。金银花中绿原酸有良好的抗氧化性。结论微波辅助提取金银花中绿原酸的最佳工艺可为其开发应用提供参考。     

速溶绿茶粉浸提工艺参数优化

目的:优化绿茶速溶茶粉的浸提工艺。方法:在单因素试验基础上,采用L16(43)正交试验设计优化绿茶速溶茶粉的浸提工艺,研究各因素对绿茶速溶茶粉提取的影响,并确定最佳工艺条件。结果:影响速溶绿茶得率的主要因素依次为浸提温度>水茶比>浸提时间;经正交试验确定茶多酚最佳提取工艺条件为浸提水温80℃、水茶比(浸提用水量与茶叶质量之比)20:1、浸提时间80min,在此最佳工艺条件下,绿茶速溶茶粉的得率为(25.1±0.1)%。结论:正交试验设计可以优化速溶茶浸提工艺,所得到的最佳工艺条件高效、可行。     

半仿生法萃取金银花中绿原酸的研究

为优化金银花中绿原酸提取工艺,以绿原酸含量为评价指标,在单因素试验基础卜进行了正交优化设计得到了半仿生法提取绿原酸的最佳工艺.根据仿生学原理并结合影响中药有效成分提取的各种因素,对提取温度、时间及料液比等3个因素进行研究.结果表明,用金银花为原料,以磷酸二氧钠-柠檬酸缓冲液为萃取剂(pH值分别为2.0、7.5和8.3),料液比(MA(金银花):MB(萃取液)=1:20),在70℃、每次提取1 h、提取3次时,绿原酸含量达到最高,为12.08 μg/mL.     

金银花中总黄酮和绿原酸加压同步提取的工艺优化

本文旨在探索加压辅助同步提取金银花中总黄酮和绿原酸的工艺。在单因素的基础上进行正交试验,考察了甲醇浓度、料液比、提取压力、提取时间和提取温度因素对总黄酮和绿原酸得率的影响。结果表明,提取压力对金银花中两类化学成分的提取有显著影响(p<0.05);优化工艺条件为甲醇浓度60%、料液比1:20 (g/mL)、提取压力2 MPa、提取时间30 min、提取温度70 ℃;工艺条件稳定,与超声波辅助提取法相比,提取效率更高。在此试验条件下,总黄酮和绿原酸的得率分别为15.66%和3.89%。本研究为金银花的开发和利用提供了新的理论依据。     

响应面优化金银花绿原酸提取工艺及抗氧化作用研究

为进一步开发利用金银花资源,采用响应面法优化金银花绿原酸提取工艺条件,分析绿原酸的抗氧化性。试验结果表明:绿原酸最佳提取条件为乙醇浓度69%、料液比1∶23(g/mL)、超声温度44℃、超声时间20 min,绿原酸提取率验证结果为6.20%。金银花绿原酸DPPH自由基半数清除率为21.09μg/mL,具有较强的抗氧化活性。金银花绿原酸与芦丁间具有一定的协同抗氧化作用,且复配体积比9∶1时协同系数SE为1.09,表明两者间协同增效作用明显。     

溶剂热法提取金银花中绿原酸的工艺研究

绿原酸为金银花的主要药效成分,具有抗菌、去除氧自由基、降血脂和升高白细胞等多种药理作用。此外,绿原酸还广泛的应用于食品保鲜剂和化妆品的抗衰老剂。本文在单因素试验的基础上,采用正交试验法,以金银花为原料,绿原酸提取率为考察指标,优化了溶剂热法提取绿原酸的提取工艺,并考察了甲醇浓度、提取温度、提取时间以及溶剂p H对绿原酸提取效果的影响。结果表明,溶剂热法提取绿原酸的最佳提取工艺条件为甲醇浓度50%、提取温度110℃,提取溶剂p H 6,提取时间30min,绿原酸的提取率为4.21%。     

喷雾干燥法制备金银花叶速溶茶的工艺优化

以金银花叶为原料,经水浴震荡提取、旋转蒸发浓缩、喷雾干燥工艺制得金银花叶速溶茶,通过测定干燥效果、产品含水量和得率,确定了喷雾干燥的最适进料浓度、进料流量、进口温度,并对所得金银花叶速溶茶进行了感官评定。结果显示:在入料浓度为3%、流速20mL/min、进口温度155℃的条件下喷雾干燥效果最好,所得金银花叶速溶茶功能成分丰富,携带、饮用方便,必将受到消费者喜爱。     

响应面法优化微波超声双辅助提取金银花绿原酸工艺

以金银花为原料,采用微波超声双辅助提取绿原酸。通过单因素实验对乙醇浓度、超声温度、超声时间、料液比、微波功率、微波时间等工艺参数进行研究,并通过响应面法优化提取工艺,建立二次多项数学模型。结果表明,单因素和响应面优化金银花绿原酸的最优工艺参数为:微波功率400W、微波时间94s、液料比42∶1mL/g、乙醇浓度70%、超声温度为60℃、超声时间60min,此条件下金银花绿原酸提取率为5.45%。     

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