山楂黄酮提取物的抗氧化活性和对癌细胞生长抑制作用

目的:研究山楂(Crataegus pinnatifida Bunge)黄酮提取物的抗氧化能力以及对人肝癌Hep-G2细胞和人肠癌Caco-2细胞生长抑制作用。方法:比较测定总黄酮含量的直接法和两种铝盐显色法,进一步采用硝酸铝盐显色法测定提取物总黄酮含量,ABTS法和DPPH法分析提取物的抗氧化活性,MTT法评价山楂黄酮提取物对细胞生长的抑制效果。结果:山楂黄酮提取物中黄酮含量占干质量的98%,清除ABTS和DPPH自由基的能力随提取物剂量的增加而升高,EC50分别为88μg/mL和112μg/mL,而标准品Trolox的EC50清除ABTS和DPPH自由基的能力分别为111μg/mL和118μg/mL。山楂黄酮提取物能够有效地抑制癌细胞的生长,且对Hep-G2细胞的抑制效果更强,Hep-G2细胞和Caco-2细胞的IC50分别约为115μg/mL和376μg/mL。结论:山楂黄酮提取物黄酮含量高,抗氧化能力强,有抑制癌细胞的作用,是一种有效的天然抗氧化剂。     

油茶籽壳总黄酮的提取及抗氧化研究

研究油茶籽壳中总黄酮类物质的提取工艺,探讨影响提取率的主要因素,通过正交试验确定最佳提取工艺。通过DPPH法﹑FRAP法﹑.OH清除能力3个体系对不同溶剂提取物的体外抗氧化能力进行研究。试验结果表明:在30倍样重的60%乙醇中浸泡后,40℃下超声波辅助萃取45 min,油茶籽壳中的总黄酮提取率为1.71%。此外,不同溶剂提取物中黄酮提取率差异很大。在DPPH体系中,油茶籽壳60%乙醇提取物的IC50为781μg/mL,清除能力强于其它溶剂提取物与对照品竹叶提取物(IC50为1 025μg/mL,主要成分为竹叶黄酮)(P0.05);60%乙醇提取物的FRAP值为1.79 mmol/L,显示出与竹叶提取物相当的还原能力;在清除羟自由基(.OH)体系中,样品质量浓度为500μg/mL时,乙醇提取物的清除效果与竹叶提取物相当;当样品质量浓度为1 000μg/mL时,乙醇提取物的清除效果稍弱于竹叶提取物。     

木瓜抗氧化活性研究

采用DPPH法、ABTS法和FRAP法三种测定法对木瓜叶和木瓜果实体外抗氧化活性进行综合评价,并分析其总多酚与总黄酮含量与抗氧化活性的关系。结果表明:木瓜6个提取物中,木瓜叶乙酸乙酯部位清除ABTS自由基及还原Fe3+(IC50=6.66μg/mL,TEAC=1293.25μmol/g)最强,其中,清除ABTS自由基活性和阳性对照BHT(IC50=6.56μg/mL)相当,还原Fe3+能力低于BHT(TEAC=2503.17μmol/g);木瓜果实乙酸乙酯部位清除DPPH自由基(IC50=48.99μg/mL)能力最强,弱于阳性对照BHT(IC50=24.49μg/mL)。木瓜叶乙酸乙酯部位清除ABTS自由基及还原Fe3+的能力可能与其多酚、黄酮含量高有关,木瓜果实乙酸乙酯部位清除DPPH自由基的能力可能也与其多酚、黄酮含量高有关。     

不同贮藏年份康砖茶主要成分差异及其抗氧化活性比较

以不同贮藏年份康砖茶为试验材料,检测其儿茶素、没食子酸和茶色素含量,测定其多酚提取物还原铁离子的能力、清除DPPH和ABTS自由基的能力,比较其抗氧化活性。结果表明:随着贮藏年份的增加,康砖茶总黄酮、茶褐素和没食子酸含量呈显著增加的趋势(p0.05)。多酚提取物FRAP·EC50(8.28μg/m L～14.55μg/m L)显著高于DPPH·EC50(4.26μg/m L～4.99μg/m L)和ABTS EC50(5.14μg/m L～5.50μg/m L),且DPPH EC50显著低于ABTS EC50(p0.05)。随着贮藏年份的增加,DPPH EC50显著降低;FRAPEC50先显著增加,后显著降低(p0.05)。贮藏期6年(YA2010)ABTS EC50显著低于其他年份(p0.05)。贮藏时间为15年(YA2001)和23年(YA1993)的康砖茶还原铁离子的能力和清除DPPH自由基的能力高于其他年份康砖茶。相关性分析表明,FRAP EC50和DPPH·EC50均与没食子酸、茶褐素呈显著负相关(p0.05);ABTS·EC50与没食子酸呈显著正相关(p0.05)。因此,康砖茶多酚提取物具有抗氧化活性。贮藏时间越长,还原能力和清除DPPH自由基能力越强,但清除ABTS自由基的能力与贮藏时间没有明显的规律性。     

利用细胞模型和化学法评价核桃叶黄酮的抗氧化活性

从八种大孔树脂中筛选出了适宜纯化核桃叶黄酮的大孔树脂,并对纯化后核桃叶黄酮的细胞内抗氧化活性、对羟自由基清除力、对DPPH自由基清除力和对超氧阴离子自由基清除力进行了研究。结果表明,AB-8型大孔树脂的纯化效果最佳,核桃叶黄酮具有明显的抗氧化活性。核桃叶黄酮对羟自由基清除率高于VC,对超氧阴离子自由基抑制率和DPPH自由基清除率低于Vc,其IC50为22.4μg/mL。核桃叶黄酮在结肠癌细胞(HT-29)中表现出明显的抗氧化活性,其抗氧化性随浓度递增。     

新疆狭叶薰衣草总黄酮抗氧化活性的研究

薰衣草是唇型科薰衣草属植物,是珍贵的中药材和食品香料。新疆伊犁具有丰富的薰衣草资源。薰衣草黄酮是新开发的一种植物类黄酮,由于其具有抗自由基、抗氧化及保护心血管等方面的生物学活性,目前已受到国内外市场的广泛关注。为了考察薰衣草黄酮的性质,本论文以新疆伊犁狭叶薰衣草为原料,对其抗氧化活性进行了较为系统的研究。实验结果表明,薰衣草总黄酮能有效的清除超氧阴离子自由基,EC50为60μg/mL;能有效的清除羟基自由基,EC50为182μg/mL;能有效的清除DPPH,EC50为189μg/mL。研究表明:薰衣草总黄酮具有较强的抗氧化活性,作为多功能的抗氧化剂,应用前景广阔。     

抗氧化剂对牛肉膏体香精的抗氧化作用

采用DPPH.法测定了油溶性抗氧化剂叔丁基对苯二酚(TBHQ)、丁基羟基茴香醚(BHA)、二丁基羟基甲苯(BHT)、VE和水溶性抗氧化剂茶多酚(TP)、迷迭香酸、竹叶黄酮七种抗氧化剂对二苯代苦味肼基自由基(DPPH.)的清除作用。其50%抑制浓度IC50分别为1.14 ug/mL、2.20 ug/mL、2.85 ug/mL、1.79 ug/mL、1.17 ug/mL、1.67 ug/mL、3.81 ug/mL。清除能力排序为TBHQ>TP>迷迭香酸>VE>BHA>BHT>竹叶黄酮。七种抗氧化剂应用于牛肉膏体香精均具有较好的抗氧化作用,加入0.1 g/kg抗氧化剂60±1℃保温30天,牛肉膏体香精的过氧化值分别为TBHQ:5.23 meq/kg、BHA:7.28 meq/kg、BHT:8.71 meq/kg、VE:9.38 meq/kg、TP:7.57 meq/kg、迷迭香酸:9.21meq/kg、竹叶黄酮:11.58meq/kg、对照组:70.84 meq/kg。抗氧化能力为TBHQ>BHA>TP>BHT>迷迭香酸>VE>竹叶黄酮。过氧化值法与DPPH.法测得的抗氧化剂抗氧化能力有较大的不同,而将油溶性的抗氧化剂和水溶性的抗氧化剂分开进行比较则两者结果较为一致。     

柚皮中活性物质的抗氧化活性研究

柚子皮中含有大量的黄酮类物质,研究柚皮中黄酮类化合物(槲皮素、芦丁、柚皮苷、橙皮苷)和香豆素类化合物(伞形花内酯)的抗氧化作用,对上述5种物质分别采用DPPH法、ABTs法、FRAP法、TBA法测定其抗氧化活性。结果表明槲皮素和芦丁具有较高的还原力,优于VC;清除DPPH自由基的能力均较高,IC50分别为1.36μg/mL和2.32μg/mL,效果优于BHT;清除ABTs+自由基的能力均较高,IC50分别为1.92μg/mL和0.86μg/mL,效果优于BHT;抗脂质过氧化的能力均较高,IC50分别为9.15μg/mL和5.84μg/mL,效果优于BHT。而伞形花内酯、柚皮苷和橙皮苷具有较低的还原力,比VC差;清除DPPH自由基的能力均较低,IC50分别为0.77 mg/mL、5.24 mg/mL和5.57mg/mL,效果比BHT差;清除ABTs+自由基的能力均较低,IC50分别为5.41 mg/mL、3.09 mg/mL和5.78 mg/mL,效果比BHT差;TBA试验表明伞形花内酯、柚皮苷和橙皮苷抗脂质过氧化效果较差。     

梅花总黄酮对黄嘌呤氧化酶的抑制作用及其抗氧化活性评价

评价了梅花总黄酮对黄嘌呤氧化酶（XOD）的抑制作用及其抗氧化活性。通过体外评价实验测定梅花总黄酮对XOD的抑制作用,并分别采用DPPH自由基法、铁离子还原法（FRAP）和血液总抗氧化能力测定法评价其抗氧化活性。结果显示,梅花总黄酮对XOD的抑制呈现浓度依赖关系,半抑制浓度（IC50值）为85.45μg/mL;梅花总黄酮清除DPPH自由基的能力强于竹叶黄酮,但弱于维生素C和芦丁;梅花总黄酮还原铁离子的FRAP值为3.38mmol/mg,是芦丁的1.44倍和竹叶黄酮的1.29倍;血液总抗氧化能力的测定结果从强到弱依次为：维生素C〉梅花总黄酮〉竹叶黄酮〉芦丁。研究表明,源自青梅花的生物总黄酮具有优良的生物抗氧化能力和显著的XOD抑制活性,可作为潜在的抗氧化应激和预防高尿酸血症的膳食功能因子进行深入研究和开发。     

云芝多糖的体外抗氧化活性研究

从清除超氧阴离子自由基、清除DPPH自由基、抑制羟基自由基的产生和还原力4个方面研究了云芝多糖的体外抗氧化效果,并同Vc进行比较.结果表明,云芝多糖对O2·清除作用明显,与Vc接近;还原力和清除DPPH·的能力比Vc差;对·OH的清除表现为在1g/L～5g/L浓度范围内,云芝多糖未达到EC50值.     

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