红树莓果实中鞣花酸的提取工艺研究

采用60%甲醇、无水乙醇、1.2mol/L的盐酸对红树莓果实中的鞣花酸进行了提取,确定了丙酮为较好的提取溶剂。考察了丙酮浓度、提取温度、料液比、提取时间4个因素对提取鞣花酸的影响,确定最佳工艺参数为:85%丙酮、料液比1∶12、提取时间为90min、提取温度80℃。采用最佳工艺条件进行提取,确定红树莓果鞣花酸含量为322μg/g。     

反相高效液相色谱法测定东北地区6 种红树莓果实中鞣花酸含量

建立反相高效液相色谱法测定东北地区6 种红树莓果实中鞣花酸含量,同时与蓝莓进行比较分析。色谱条件：色谱柱SinoChrom DS-BP C18（150 mm×4.6 mm,5 μm）;流动相为CH3OH-0.3%磷酸（40∶60,V/V）;流速1 mL/min,柱温30 ℃,检测波长254 nm。结果表明：鞣花酸得到很好地分离,鞣花酸含量在0.1～1 μg范围内与峰面积呈良好的线性关系,R2为0.999 3。精密度实验相对标准偏差为0.06%,重复性实验相对标准偏差为0.09%,稳定性实验相对标准偏差为0.39%,平均加样回收率为93.00%～98.62%,相对标准偏差为0.21%～0.42%,该方法简单、准确、重复性好。测得不同品种红树莓果实中总鞣花酸含量为39.10～155.98 mg/100 g;游离鞣花酸含量为1.24～8.26 mg/100 g,红树莓中含有丰富的鞣花酸,具有潜在的开发利用价值。     

响应面法优化树莓鞣花酸提取工艺及其体外抗氧化活性

本研究旨在通过微波辅助提取法确定树莓鞣花酸的最佳提取工艺,并对其抗氧化活性进行研究。以红树莓为实验原料,使用乙醇提取溶剂,采用微波辅助溶剂法提取红树莓中鞣花酸,通过单因素试验与响应面试验优化红树莓中鞣花酸提取工艺,利用高效液相色谱(HPLC)法对鞣花酸进行分析测定,并对其抗氧化性进行研究。结果表明:响应面试验优化出最佳提取条件为:提取时间1.8 min、提取温度60 ℃、乙醇浓度50%、液料比19:1、微波功率411 W,此条件下测得鞣花酸提取量为(82.75±1.05) mg/100 g,高于传统盐酸水解法在最佳提取条件下所测树莓鞣花酸提取量。实际结果与理论预测高度吻合,因此本实验得到的最优条件准确可靠有参考应用价值。微波辅助溶剂法所得鞣花酸对羟自由基清除能力、清除DPPH自由基能力都显著高于传统盐酸水解法所得鞣花酸对羟自由基清除能力,清除DPPH自由基能力,说明微波辅助溶剂提取法,不但提取时间短暂,提取溶剂用量少,而且更好的保护了树莓鞣花酸的抗氧化活性,可为树莓鞣花酸工业生产提供一定参考。     

树莓叶中鞣花酸提取工艺的研究

研究树莓叶中鞣花酸的提取工艺,采用液相色谱法测定鞣花酸含量。设计以考察乙醇浓度,提取时间,提取温度,料液比为四因素三水平的正交试验。结果标明:影响鞣花酸提取率的先后顺序是:乙醇浓度→提取温度→提取时间→料液比;最佳提取工艺为乙醇浓度80%,提取时间60 min,提取温度95℃,料液比3∶140(g/m L)。     

黑莓、树莓不同发育时期叶片鞣花酸与抗氧化、糖类物质的相关性分析

本研究拟在初步揭示悬钩子属浆果不同发育时期叶片中鞣花酸的变化规律。以黑莓、树莓及杂交类型共21个品种不同时期叶片为试材,用超声辅助溶剂提取法提取叶片中鞣花酸,用紫外分光光度法快速检测鞣花酸含量。在此基础上,选取其中5个品种分析评价了叶片抗氧化能力、抗氧化物质含量及糖类物质含量与鞣花酸含量的关系。结果表明,黑莓、树莓鞣花酸在嫩叶中含量较高,随着叶片的发育和衰老呈下降趋势,以黑莓‘宝森’嫩叶鞣花酸含量最高达39.622 mg/g,以树莓‘哈瑞泰兹’老叶中鞣花酸含量最低为7.649 mg/g。进而分析5个品种叶片的抗氧化能力及抗氧化物质含量,发现其与鞣花酸含量变化趋势相似,而叶片中糖类物质含量与鞣花酸含量变化呈负相关。研究结果为黑莓、树莓叶片中鞣花酸的功能研究及进一步开发利用提供部分基础理论依据。     

高效液相色谱分析蓝莓发酵液中鞣花酸和没食子酸

建立了高效液相色谱法测定蓝莓发酵液中鞣花酸含量和没食子酸含量的两种方法。鞣花酸的测定条件：Waters symmetry C18色谱柱,柱温25℃,流动相为46∶2∶52的甲醇—乙酸乙酯—KH2PO4/H3PO4溶液,流速0.8m L/min,检测波长254nm,检测蓝莓发酵液中鞣花酸平均回收率为92.68%,RSD为0.97%。没食子酸的测定条件：Waters symmetry C18色谱柱（250×4.6mm,5μm）,柱温35℃,流动相为甲醇：水（0.1%磷酸）=10∶90,流速为1.0m L/min,检测波长273nm,该方法检测蓝莓发酵液中没食子酸平均回收率为99.0%,RSD为0.73%。两种方法均操作简单快速,重现性好,准确度高,可分别用于香菇等食用菌发酵蓝莓制品中鞣花酸和没食子酸含量的测定。     

响应曲面法优化红树莓多糖提取工艺

红树莓是具有多种维生素、矿物质、多酚、鞣花酸、SOD、黄酮类和多糖的天然产物,并且其利用价值和应用途径极高。本实验以红树莓为原料,采用热水法提取红树莓多糖,选择料液比、提取温度和提取时间作为单因素实验,并采用响应曲面法进行优化,优化后的工艺条件为:料液比1∶19.83(g/m L)、提取温度70.54℃、提取时间0.99h,多糖得率预测值为9.39%,进行验证试验,粗多糖的得率为10.69%,与预测值9.39%相差不多,表明响应曲面优化的工艺条件可行,根据实际条件,确定最佳提取工艺条件为:当料液比为1∶20.00(g/m L)、提取温度71℃、提取时间59min,此时,红树莓多糖的得率为10.69%。     

树莓与蓝莓中多酚类成分的HPLC测定

利用HPLC法对树莓与蓝莓中的生理活性成分进行含量测定。HPLC法采用Kromasil C18色谱柱(150 mm,4.6 mm);流动相采用色谱纯乙腈(A)-含0.1%磷酸水溶液(B)梯度洗脱,0~16 min,5%A;19 min,10%A;23 min,13%A;40 min,14%A;43 min,17%A;48 min,22%A;51 min,24%A;52 min,24%A;58 min,26%A;60 min,30%A;65 min,60%A;68 min,70%A;72 min~78 min,100%A;流速为1 mL/min;柱温30℃;检测波长为280 nm;每次进样10μL,测定树莓与蓝莓95%乙醇提取物中没食子酸、原儿茶酸、儿茶素、表儿茶素、原花青素B2、矢车菊素、鞣花酸、树莓酮、白藜芦醇、水杨酸的含量;这十种多酚类成分在三种浆果中含量高低不等,其中鞣花酸含量在黑树莓中最高(0.97μg/g),红树莓次之(0.51μg/g),蓝莓最低(0.36μg/g)。蓝莓与树莓中富含多种多酚类物质,是其具有多种生物活性的物质基础。     

高效液相色谱法测定普洱熟茶中鞣花酸含量

文章建立了普洱熟茶中鞣花酸含量的高效液相色谱测定方法。 色谱柱为 Agilent ZORBAX SB-C18柱,流动相为 0.2%磷酸水溶液-乙腈(体积比 85∶15),等度洗脱,流速 1 mL/min,进样量 10 μL,检测波长 245 nm,采用外标法定量。 结果表明,鞣花酸质量浓度在 0.6～60 mg/L 范围内与峰面积呈良好的线性关系(R²=0.9996),最低检出限为 13.5 mg/kg,最低定量限为 45.0 mg/kg。 该方法具有快速、准确、灵敏度高、重现性好的特点,可用于普洱熟茶中鞣花酸的定量检测及其质量控制。     

大孔树脂分离纯化树莓酮的工艺研究

为探究大孔树脂纯化红树莓果中树莓酮的最佳工艺,以红树莓果中得到的粗提液为原料,采用气相色谱法测定树莓酮含量,以吸附率和解析率为指标,通过静态吸附及解析实验对4种大孔树脂(AB-8、D101、DA-201、X-5)进行筛选,得出最优大孔树脂并进行树莓酮的分离纯化实验。最终确定大孔树脂分离纯化红树莓中树莓酮的最佳工艺条件为:选择AB-8型大孔树脂,纯化浓度为3.155μg/mL,上样体积为30mL,吸附流速为1mL/min;收集用浓度为30%～70%乙醇溶液洗脱的树莓酮纯化液,洗脱剂用量为100m L,洗脱流速为1.5mL/min。经验证实验得树莓酮纯度可达51.33%,说明AB-8型大孔树脂能较好的用于树莓酮的纯化工艺。     

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