香榧仁油中不同形态酚类物质的提取优化及抗氧化能力评价

为提高香榧仁油中不同形态酚类物质的提取得率及探究不同储藏方式下各形态酚类物质的抗氧化能力变化规律,通过单因素实验优化香榧仁油中可溶性部分的游离态酚、酯化态酚以及不溶性结合态酚的提取条件,应用优化后的方法提取常温储藏和冷藏(4℃)1年后的香榧仁油中的不同形态酚类物质,分析其总酚含量并测定DPPH、ABTS自由基清除活性和铁离子还原能力。结果表明：使用甲醇-丙酮-水(7∶7∶6)萃取分离香榧仁油中可溶、不溶性酚类物质效果较好;可溶酯化态酚和不溶性结合态酚碱解的最适碱液浓度、时间和温度分别为0.5 mol/L、6 h、30℃和0.5 mol/L、6 h和40℃;可溶游离态酚及水解后释放的结合态酚使用石油醚-乙酸乙酯(1∶1)提取4次效率较高。常温储藏和冷藏条件下香榧仁油中不同形态酚类物质按含量排序分别为：游离态>酯化态>不溶性结合态、酯化态>游离态>不溶性结合态;冷藏香榧仁油中的酚含量总和、3种形态酚的DPPH及ABTS自由基清除活性和结合态酚的铁离子还原能力均高于常温储藏香榧仁油,冷藏油中酚类物质抗氧化能力总体优于常温储藏油。     

超高压预处理对西番莲果皮抗氧化能力及对HepG2细胞氧化损伤保护作用的影响

酚类化合物以游离态、酯化态和不溶性结合态存在于植物中,本实验通过超高压预处理紫色西番莲果皮(the peel of Passiflora edulis Sims,PEP),研究超高压预处理后PEP游离态、酯化态和结合态酚类化合物的多酚含量、抗氧化活性和细胞保护作用的变化,从而确定超高压预处理对PEP抗氧化能力及对Hep...     

不同酿酒高粱酚类物质含量测定及抗氧化活性比较

以6种酿酒高粱籽粒为研究对象,分别比较其游离态与结合态总酚、总黄酮、酚酸物质种类及含量,并对其抗氧化活性进行 分析。 结果表明,不同酿酒高粱品种游离态总酚、总黄酮;结合态总酚、总黄酮含量分别在135.47～274.38 mgGAE/100 g、94.60～ 148.31 mg/100 g;618.27～1 383.17 mgGAE/100 g、123.06～434.84 mg/100 g。 酿酒高粱籽粒中游离态酚酸以阿魏酸、丁香酸与没食 子酸为主,平均含量分别为611.19 μg/g、380.66 μg/g、359.34 μg/g;结合态酚酸以阿魏酸、丁香酸为主,平均含量为1 608.33 μg/g、 376.78 μg/g。 酿酒高粱籽粒中游离态与结合态总酚ABTS抗氧化能力值分别占总ABTS能力值14.6%与85.4%;酿酒高粱籽粒中游离 态与结合态总酚FRAP抗氧化能力值占总FRAP能力值14.3%与85.7%。 酿酒高粱籽粒具有丰富的酚类物质,良好的抗氧化活性,且品 种间有显著性的差异（P＜0.05）。     

核桃仁发育过程中不同形态酚及其抗氧化活性的动态变化

阐明发育期核桃仁中3种不同形态酚（游离、酯化和结合）及其单体酚组成的变化,探究酚类成分与抗氧化能力的关系,为深入了解核桃功能性成分形成规律和深化功能性产品开发提供参考。以核桃品种‘寒丰’为对象,运用UPLC-MS/MS测定3种形态酚组成,分光光度计法测定核桃的羟自由基清除能力,皮尔逊相关分析用于研究酚类物质与羟自由基清除能力的相关性关系。在核桃仁发育过程中,酚形态中以游离态为主且占比大于58%;3种形态总酚含量最高值均出现在采前63 d,分别为10.47 mg/g（游离态）、2.76 mg/g（酯化态）、1.28 mg/g（结合态）;鞣花酸、咖啡酸、绿原酸等单体酚的3种形态含量随着核桃仁发育显著降低58.03%-88.83%;单体酚含量与抗氧化活性呈现显著相关性,相关系数为0.63-0.97。核桃仁3种形态总酚含量和抗氧化活性最大值均出现在未成熟早期,游离态是核桃仁中提供抗氧化活性的酚类物质主要形态,并且核桃仁发育过程中单体酚的抗氧化能力与成熟度、酚形态有关。这些发现将对核桃的适时采摘和营养管理以及核桃仁深度开发利用、产业提质增效等提供重要的基础数据和理论参考。     

成熟期对冬枣多酚含量及其抗氧化活性的影响

研究了全绿、绿白、半红和全红四个成熟期冬枣果实的果皮和果肉中游离态、酯化态和结合态的酚含量以及其总抗氧化能力、清除DPPH自由基和铁还原能力的变化。结果表明,冬枣果实酚类物质主要以游离态和酯化态形式存在于果皮当中,全红期果皮以结合态为主。冬枣果皮中游离态和酯化态酚类物质对总抗氧化能力、清除DPPH自由基和铁还原能力起主要作用。半红期冬枣果实酚含量最多以及其抗氧化活性最为突出。      

紫色百香果果皮多酚存在形式及抗氧化活性

以紫色百香果果皮为材料,采用两项溶剂萃取的方法提取分离百香果果皮的游离态、酯化态及结合态多酚,测定其多酚含量和体外抗氧化活性,并采用电喷雾电离质谱（electrospray ionization mass spectrometry,ESI-MS）对3种形式多酚进行成分分析。结果表明,百香果果皮中游离酚含量最多,为0.641 3 mg GAE/g DW;酯化酚次之,为0.529 0 mg GAE/g DW;结合酚最少,为0.153 3 mg GAE/g DW;游离酚、酯化酚和结合酚的DPPH自由基清除率分别为43.1%、39.5%、24.8%;铁离子还原能力（ferric ion reducing antioxidant powder,FRAP）值分别为 140、117、86 mmol/L,羟基自由基清除率分别为24.0%、22.9%、18.3%。不同存在形式百香果果皮多酚的抗氧化能力大小表现为游离酚＞酯化酚＞结合酚;百香果果皮中3种形式多酚在种类和组分上存在着很大的差异。     

不同粒色青稞酚类化合物含量与抗氧化活性的差异及评价

为了比较不同粒色青稞中游离态及结合态酚类化合物的含量及其抗氧化活性的差异。选用52份不同粒色青稞种质资源,采用化学法分析其青稞全籽粒中游离态及结合态总酚、总黄酮含量,通过DPPH、ABTS+·自由基清除能力及FRAP铁离子还原能力评价其体外抗氧化能力差异,利用主成分分析法客观评价其酚类化合物含量及抗氧化活性的品种排名。结果表明:结合酚是有色青稞酚酸的主要存在形式,游离黄酮是青稞中黄酮类物质的主要存在形式,组间含量差异显著,黑色组青稞的总酚类化合物含量较高;不同形态酚类物质对自由基清除能力的强弱具有选择性,游离态酚类化合物含量在一定程度上决定DPPH和ABTS自由基清除能力大小,FRAP铁离子还原能力受青稞中游离态及结合态酚类化合物含量的共同影响;不同粒色组青稞的酚类化合物含量及抗氧化活性存在品种间差异,主成分分析筛选出紫色、蓝色、黑色、黄色组青稞中酚类物质含量及抗氧化活性最高的品种分别为云青2号、循化亮蓝、947和短白青稞。     

溶剂提取对青稞中不同形态多酚组成及抗氧化活性的影响

为研究不同极性溶剂对青稞全谷物中不同形态酚类化合物含量、组成及抗氧化性的影响,建立适宜于青稞全谷物中多酚提取的方法。以4?个不同品种青稞为原料,比较4?种不同溶剂及酸法、碱法分别对青稞中游离酚和结合酚含量、组成与抗氧化活性的影响。结果表明,所有提取试剂中80%丙酮溶液提取的游离态总酚含量（139.79～235.96?mg/100?g）及总黄酮含量（9.88～15.52?mg/100?g）最高,酸法提取的青稞结合态总酚含量是碱法的1.9～3.1?倍,结合态黄酮含量是碱法的1.3～2.9?倍;80%丙酮溶液提取物中检测到8～18?种青稞游离酚类化合物,且酚类化合物含量显著高于其他溶剂,绿原酸、苯甲酸、儿茶素、槲皮素、芦丁是其主要的游离酚类化合物。与碱法相比,酸法能释放出更多的结合酚类化合物类型及含量,没食子酸、p-香豆酸、丁香酸、苯甲酸、藜芦酸、橙皮苷是其主要的结合酚类化合物;参试青稞80%丙酮溶液提取物显示出最高的1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力（852.56～1?484.18?μmol/100?g）,2,2’-联氮-双-（3-乙基苯并噻唑啉-6-磺酸）二铵盐（2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS）自由基清除能力（358.93～518.09?μmol/100?g）及铁离子还原能力（ferric ion reducing antioxidant power,FRAP）（1?250.55～2?041.16?μmol/100?g）。酸法水解参试青稞结合酚DPPH自由基清除能力、FRAP、ABTS＋?清除能力分别是碱法水解的7.6～10.3、1.2～1.8?倍和1.1～1.3?倍。因此,80%丙酮溶剂和酸法分别是青稞中游离酚与结合酚的适宜提取溶剂,且本研究表明青稞全谷物中富含丰富的酚类物质,是一种潜在的天然抗氧化剂来源。     

玫瑰蜂花粉中不同存在形态酚类物质的组成及其抑制B16黑色素瘤细胞的活性

本文研究了玫瑰蜂花粉中游离态和结合态酚酸类物质含量和组成;采用铁离子还原能力、ABTS和DPPH自由基清除能力三种模型评价其抗氧化能力;同时测定了其对蘑菇酪氨酸酶活性的抑制作用;并进一步研究了对B16细胞的增殖形态、黑色素含量和酪氨酸酶活性的影响。结果表明,蜂花粉中游离态和结合态的总酚含量分别为23.36和1.47 mg GAE/g干重(DW),总黄酮含量为19.12和2.42 mg RE/g DW。酚酸类物质大多以游离态形式存在,富含槲皮素和芦丁,而结合态中鞣花酸和3,4-二甲氧基苯甲酸含量较高;游离态和结合态多酚在三种模型中均显示较好的抗氧化活性;抑制蘑菇酪氨酸酶活性IC50分别为22.26和26.34μg/m L,显著高于Vc;一定程度上影响了B16细胞的增殖和形态,同时显著降低细胞内相对黑色素含量和酪氨酸酶活性。玫瑰蜂花粉中不同形态多酚的活性与其酚酸的含量和组成有直接的关系。     

大花罗布麻不同部位酚类物质含量及其抗氧化活性比较研究

目的：比较大花罗布麻根、茎、叶、花4 个部位中游离态和结合态酚类物质的含量和抗氧化活性的差异,并分析含量与抗氧化活性之间的相关性。方法：采用Folin-Ciocalteu法、NaNO2-Al(NO3)3法分析罗布麻的根、茎、叶、花4 个部位的游离态和结合态总多酚、总黄酮含量,采用DPPH自由基清除能力、ABTS+·清除能力和铁离子还原能力3 种方法评价其体外抗氧化能力差异。结果：大花罗布麻总酚含量次序为：叶＞根＞花＞茎,各样品间存在显著性差异（P＜0.05）。各部位游离酚、结合酚和总多酚含量分别介于3 560.19～6 273.23、13.45～22.01和3 582.2～6 286.68 mg GAE/100 g干质量,其游离态多酚占总酚含量百分比平均为99.60%;游离态黄酮、结合态黄酮和总黄酮含量分别介于1 080.30～2 488.21、9.69～28.59、1 106.81～2 516.80 mg RE/100 g 干质量,其游离态黄酮占总黄酮含量的百分比平均为98.64%。大花罗布麻叶提取物清除DPPH 自由基、ABTS+·能力和总还原力最强,抗氧化活性与总酚含量之间具有良好的线性关系（r＞0.950 0）。结论：大花罗布麻各部位中含有较丰富的酚类物质,具有较强的抗氧化活性。     

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