不同干燥方法对淫羊藿多糖化学性质和抗氧化活性的影响

为研究不同干燥方法对淫羊藿多糖化学性质及抗氧化活性的影响,以粗毛淫羊藿为材料制备多糖。测定热风干燥多糖(EAP-H)、真空干燥多糖(EAP-V)和真空冷冻干燥多糖(EAP-F)的中性糖、糖醛酸和蛋白质含量,单糖组成及DPPH自由基、羟基自由基和超氧阴离子的清除能力。结果表明:淫羊藿多糖为含有少量蛋白质的酸性多糖,不同干燥方法将会影响其单糖组成和糖醛酸含量;EAP-F糖醛酸含量最高并具有最强的DPPH自由基、羟基自由基和超氧阴离子清除能力。因此,真空冷冻干燥是制备淫羊藿多糖的最佳干燥方法。     

淫羊藿药渣多糖体外抗氧化活性研究

以提取过黄酮的淫羊藿药渣为原材料,热水法提取多糖,测定淫羊藿药渣多糖的总糖含量、糖醛酸含量和蛋白质含量,并对多糖结构进行红外光谱分析。通过体外抗氧化实验研究其对DPPH自由基、超氧阴离子和羟基自由基的清除能力。结果表明,淫羊藿药渣多糖的总糖质量分数为73.39%,糖醛酸质量分数为6.33%,蛋白质质量分数为1.87%,对DPPH自由基、超氧阴离子和羟基自由基的最大清除率分别为79.96%、92.77%和69.12%,其IC50值分别为0.26、0.03、0.76mg/mL。      

淫羊藿药渣多糖体外抗氧化活性研究

以提取过黄酮的淫羊藿药渣为原材料,热水法提取多糖,测定淫羊藿药渣多糖的总糖含量、糖醛酸含量和蛋白质含量,并对多糖结构进行红外光谱分析。通过体外抗氧化实验研究其对DPPH自由基、超氧阴离子和羟基自由基的清除能力。结果表明,淫羊藿药渣多糖的总糖质量分数为73.39%,糖醛酸质量分数为6.33%,蛋白质质量分数为1.87%,对DPPH自由基、超氧阴离子和羟基自由基的最大清除率分别为79.96%、92.77%和69.12%,其IC50值分别为0.26、0.03、0.76mg/mL。     

蓬莪术多糖体外抗氧化活性研究

以多年生草本药用植物蓬莪术根茎为原材料,热水浸提法提取多糖,测定蓬莪术多糖的总糖含量、糖醛酸含量和蛋白质含量,并对蓬莪术多糖结构进行红外光谱分析。通过体外抗氧化实验研究蓬莪术多糖对自由基的清除能力以及总还原能力。结果表明,蓬莪术多糖的总糖质量分数为56.13%,糖醛酸质量分数为8.65%,蛋白质质量分数为4.53%。体外抗氧化活性研究结果表明对DPPH自由基、羟基自由基和超氧阴离子有明显清除作用和较强的还原能力,其清除自由基的IC50值分别为0.29、0.44、0.36mg/m L。      

蓬莪术多糖体外抗氧化活性研究

以多年生草本药用植物蓬莪术根茎为原材料,热水浸提法提取多糖,测定蓬莪术多糖的总糖含量、糖醛酸含量和蛋白质含量,并对蓬莪术多糖结构进行红外光谱分析。通过体外抗氧化实验研究蓬莪术多糖对自由基的清除能力以及总还原能力。结果表明,蓬莪术多糖的总糖质量分数为56.13%,糖醛酸质量分数为8.65%,蛋白质质量分数为4.53%。体外抗氧化活性研究结果表明对DPPH自由基、羟基自由基和超氧阴离子有明显清除作用和较强的还原能力,其清除自由基的IC50值分别为0.29、0.44、0.36mg/m L。     

不同产地板蓝根多糖体外清除自由基活性的比较

采用邻二氮菲-Fe~(2+)氧化法测定板蓝根多糖对羟基自由基(·OH)的清除作用;采用邻苯三酚自氧化法检测超氧阴离子自由基(·O_2~-)的清除作用;采用DPPH孤电子配对法测定DPPH自由基的清除作用。结果表明,在羟基自由基体系中,菘蓝根多糖显示较强的清除作用,清除率为52.60%;草大青根和马蓝根多糖最高分别可达到41.29%,39.35%;在超氧阴离子自由基体系中,菘蓝根多糖、草大青根和马蓝根多糖的清除率最高分别可达到50.00%、39.75%、39.15%;在DPPH自由基体系中,3种多糖最高清除率为42.75%。     

青天葵多糖的分离纯化、结构表征及其抗氧化活性分析

对水提醇沉获得的青天葵粗多糖进行分离纯化,并对多糖组分进行分析表征和体外抗氧化活性评价。结果表明,用DEAE-52纤维素及葡聚糖凝胶G-100柱色谱分离纯化出的多糖组分NFP-2分子质量为1150 kDa,总糖含量为82.64%,糖醛酸含量为16.65%,蛋白质含量为6.38%。NFP-2由半乳糖、阿拉伯糖、甘露糖、葡萄糖、鼠李糖、半乳糖醛酸组成,摩尔比为21.27:13.21:5.26:3.02:2.82:1,其为不含三螺旋结构的酸性多糖,糖苷键构型为β-构型。体外清除自由基试验结果显示,NFP-2对羟基自由基（IC₅₀ 7.95 mg/mL）和超氧阴离子自由基（当浓度为0.5 μg/mL时,清除率为60%）均有明显清除作用;当NFP-2浓度为10 mg/mL时,ABTS阳离子自由基的清除率为35.44%;当NFP-2浓度为120 μg/mL时,DPPH自由基清除率为17%。     

香菇菌丝体多糖的分离纯化和抗氧化作用

采用超声破碎和热水浸提相结合的方法提取香菇菌丝体多糖,通过L9(34)正交试验考察料液比、浸提温度、超声强度和浸提时间对多糖提取的影响,确定香菇菌丝体多糖最佳提取条件。利用D EA E-5 2离子交换和SephadexG100凝胶过滤层析纯化香菇菌丝体多糖,紫外扫描和薄膜电泳方法鉴定多糖的纯度;采用DPPH自由基、超氧阴离子自由基和羟自由基清除实验及血浆丙二醛的生成抑制作用和抑制H2O2诱导红细胞氧化溶血检测多糖的抗氧化性。结果表明:香菇菌丝体多糖最佳提取条件为料液比1:15、浸提温度90℃、超声波破碎功率400W、浸提时间3h,最适条件下鲜菌丝体的多糖提取量为3.38‰;纯化后的多糖(LMPⅡ)具有清除超氧阴离子自由基和羟自由基活性的能力,能够抑制血浆丙二醛的生成,抑制H2O2诱导红细胞氧化溶血,且呈现一定效量关系。显示纯化的香菇菌丝体多糖具有较强的抗氧化作用。     

苦荞麦多糖的抗氧化作用

为进一步开发利用苦荞资源,研究苦荞麦多糖的抗氧化性。通过邻苯三酚自氧化法、水杨酸法比色法分别测定苦荞麦多糖清除超氧阴离子自由基(O2-·)以及羟基自由基(·OH)的效果。结果表明不同浓度的苦荞多糖能显著地清除超氧阴离子自由基和羟基自由基,随着苦荞麦多糖浓度的升高其抗氧化性作用逐渐增强。     

滑菇多糖抗氧化活性研究

利用化学发光法检测滑菇多糖(Pholiota nameko polysaccharides,PNP)对超氧阴离子自由基(O-2·)、羟自由基(OH·)、脂自由基(R·)、抗氧化;单线态氧(1O2)的清除能力,同时检测了滑菇多糖对小鼠肝匀浆以及肝线粒体丙二醛(MDA)氧化抑制作用.实验结果表明,滑菇多糖四种活性氧自由基均具有较好的清除作用,同时对肝匀浆以及肝线粒体中丙二醛(MDA)氧化具有很强的抑制作用.滑菇多糖具有很好的抗氧化作用.     

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