莲子胚芽油体外抗氧化能力的研究

采用DPPH法和化学发光法对比研究了莲子胚芽油和VE、VC、茶籽油对1,1-二苯基-2-三硝基苯肼自由基（DPPH·）及超氧阴离子（O2-·）、羟自由基（·OH）及过氧化氢（H2O2）等诱导有机体突变的物质的清除作用。结果表明：莲子胚芽油具有清除DPPH自由基、超氧阴离子自由基（O2-·）、羟自由基（·OH）及过氧化氢（H2O2）的作用,表现为中等强度抗氧化活性,半清除率IC50分别48.90、13.48、3.13、0.59mg/mL,明显比茶籽油清除自由基的抗氧化效果好。     

黑加仑花色苷体外抗氧化活性相关性研究

采用清除OH·能力、清除O2-·能力、抗脂质过氧化能力和还原能力对黑加仑花色苷进行体外抗氧化活性的研究,并对这4种抗氧化方法进行相关性分析.结果表明,黑加仑花色苷具有良好的抗氧化活性.黑加仑花色苷含量与OH·清除率、O2-·清除率、抗脂质过氧化抑制率和还原能力有显著的相关性(相关系数r分别为0.9992、0.9858、0.9742、0.9976),呈明显的量效关系.OH·清除能力、O2-·清除能力及抗脂质过氧化能力的IC50值分别为5 1.66μg/mL、107.82.μg/mL、90.52μg/mL.进行4种抗氧化方法的相关性分析,其中还原能力和脂质过氧化抑制率的相关性最高(r=0.9970),O2-·清除率和脂质过氧化抑制率的相关性最低(r=0.9498).     

猕猴桃籽油的体外抗氧化活性

以猕猴桃籽油为原料,采用体外抗氧化实验模型研究其抗氧化活性。通过测定猕猴桃籽油还原力和DPPH自由基、超氧阴离子自由基(O2-·)、H2O2以及羟自由基(·OH)清除实验,以VC为阳性对照,探讨猕猴桃籽油的抗氧化性能。结果表明:猕猴桃籽油的还原能力随其质量浓度的增加而增强,对DPPH自由基、O2-·、H2O2以及·OH的清除率随质量浓度的增加而升高,其中对O2-·的清除效果比VC更明显,对其他自由基的清除效果却比VC弱;猕猴桃籽油对O2-·、H2O2、·OH的IC50分别为0.078、0.1、0.2mg/mL,表明猕猴桃籽油清除O2-·的效果最好。     

槐角黄酮的体外抗氧化活性研究

选用回流法提取槐角中黄酮类化合物,采用DPPH·法、邻苯三酚自氧化法和邻二氮菲法,测定了槐角黄酮对DPPH·、O2-·、·OH的清除率,并与维生素C(VC)比较,进行槐角黄酮的体外抗氧化活性研究.结果表明,槐角黄酮具有一定的抗氧化能力,在一定浓度范围内,清除自由基能力与其浓度呈正相关性.与阳性对照VC相比,槐角黄酮对DPPH·的清除作用较弱,IC50为0.0192mg/mL;而对O2-、、·OH的清除作用较强,IC50分别为0.0127、0.0160mg/mL.这表明槐角黄酮具有一定的抗氧化能力.     

黄鳍金枪鱼皮胶原肽酶解工艺及抗氧化活性研究

以金枪鱼皮为原料,以肽得率、水解度和感官评价为指标,确定金枪鱼皮胶原肽酶解的最优工艺条件是:中性蛋白酶,酶解时间4 h,酶添加量1 000 U/g,此时肽得率29.03%。体外抗氧化能力测定结果:金枪鱼皮胶原蛋白酶解物具有一定的抗氧化活性,总还原力是VC总还原力的60%;与VC相比,DPPH·清除率(IC50=0.43 mg/m L)、O22-清除率(IC50=3.67 mg/m L)、卵磷脂过氧化物清除率(IC50=14.67 mg/m L)较低,·OH清除率(IC50=0.39 mg/m L)、H2O2清除率(IC50=0.05 g/m L)较高。该酶解物能显著降低油脂的过氧化值,然而降低幅度略低于VC。     

裙带菜孢子叶岩藻黄质提取工艺与抗氧化活性的研究

以裙带菜孢子叶为原料,采用超声波法和酶解法复合提取工艺制备岩藻黄质。考察提取溶剂、料液比、超声时间、酶解时间和酶解温度等因素对岩藻黄质提取量的影响,确定最优条件为:提取剂为乙醇:丙酮(3:1)、料液比1:30(w:v)、超声时间10 min、酶解时间35 min、酶解温度50℃时,岩藻黄质提取量达到最佳(0.75±0.03)mg/g。同时采用电子自旋共振波谱技术检测岩藻黄质对DPPH、羟基自由基的清除率,结果表明,岩藻黄质对DPPH和羟基自由基的清除能力随浓度的升高而增强,对DPPH清除率的IC50为3.93μg/m L,对羟基自由基清除率的IC50为30.07μg/m L,表明岩藻黄质具有较强的抗氧化性。     

红曲色素组份分离及其抗氧化活性研究

采用不同展开剂对红曲色素进行薄层层析,得到7种红色素、4种黄色素、2种橙色素,共13个色素组份.采用·OH体系、O2·-体系和DPPH体系三种抗氧化模型,分别测定了不同色素组份的抗氧化活性.结果表明,红色色素组份和橙色色素组份在上述3种氧化模型中均表现出较高的抗氧化活性.其中,红色色素组份2的抗氧化效果最好,在40μg/mL的质量浓度下,对·OH的清除率为32%,比同浓度的Vc高20%;对DPPH的清除率达64%,比同浓度的Vc高41%;对O2·-的清除率达到34%.     

葡萄籽原花青素抗氧化作用的研究

采用亚油酸体系、脂质体体系、DPPH.及O2-.研究葡萄籽原花青素提取物的抗氧化活性,结果表明,葡萄籽原花青素具有很强的抗氧化和自由基清除能力,在亚油酸及脂质体体系中,原花青素的抗氧化活性高于VC和VE,并与VC、VE具有协同增效作用,随着浓度的增加,其抗氧化能力可以与合成抗氧化剂BHT相近;原花青素对DPPH.自由基的清除能力优于VC、VE及BHT,半抑制浓度分别为:原花青素1.8μg/mL、VC 2.5μg/mL、VE 6.3μg/mL、BHT 3.5μg/mL。对O2-.的清除能力优于VE而与VC相近,半抑制浓度分别为原花青素15.4μg/mL、VC 14.5μg/mL、VE 177μg/mL。     

海南蒲桃果实原花青素的体外抗氧化活性

以半制备HPLC纯化的海南蒲桃原花青素为供试样品,研究其体外抗氧化活性。结果表明:海南蒲桃原花青素对DPPH自由基的半抑制剂量IC50为4.448μg/mL,超氧阴离子自由基(O-2.)的半抑制剂量IC50为5.718μg/mL,羟自由基(.OH)的半抑制剂量IC50为60.490μg/mL;海南蒲桃原花青素对亚油酸脂质过氧化半抑制剂量IC5 0为117.091μg/mL,总抗氧化、还原力明显高于VC;金属离子螯合力高于EDTA。提示海南蒲桃原花青素具有较强的清除自由基与抗氧化活性等体外活性。     

超声辅助提取盐碱地苦菜多酚及其抗氧化活性研究

以总多酚提取率为指标,采用单因素及正交试验优化苦菜多酚的提取工艺条件;以自由基清除率为指标,用抗坏血酸作对照品,研究苦菜多酚的抗氧化活性。结果表明,最佳提取工艺条件为超声功率为150 W、乙醇浓度60%、超声温度55℃、超声时间40 min、料液比1∶50 (g/mL)、提取3次。在该工艺条件下,苦菜多酚的提取率为65.3 mg/g。苦菜多酚对DPPH·清除作用的IC50值为1.44μg/mL,对·OH清除作用的IC50值为83.72μg/mL,其清除能力均强于抗坏血酸,表明盐碱地苦菜多酚有较好的抗氧化活性。     

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