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1.
葡萄籽原花青素聚合度与自由基清除能力关系的研究   总被引:2,自引:0,他引:2  
孙芸  徐宝才  谷文英  熊晓辉 《食品科学》2007,28(12):423-428
采用DPPH·及化学发光法,研究葡萄籽原花青素不同聚合度组分的自由基清除能力。结果表明,原花青素对DPPH·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、VC2.5μg/ml、VE6.3μg/ml、BHT3.5μg/ml。对O2·的清除能力优于VE而与VC相近。以质量浓度(μg/ml)表示时,原花青素对DPPH·的清除作用与聚合度无关,对HO·、O2·的清除能力随着聚合度的升高而下降。但以摩尔浓度(μmol/L)表示时,原花青素的自由基清除能力基本上随着聚合度的增加而提高。原花青素的抗氧化和自由基清除能力可能与所处的溶剂环境有关,水相体系中原花青素分子中单位酚羟基的活性随着聚合度的增加而下降。  相似文献   

2.
葡萄籽原花青素的聚合度与抗氧化活性关系   总被引:11,自引:1,他引:10  
采用亚油酸体系和脂质体体系研究葡萄籽原花青素不同聚合度组分的抗氧化活性。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,并且随着浓度的增加其抗氧化能力与合成抗氧化剂BHT相近。聚合度对原花青素抗氧化作用的影响较大,单体对脂质体体系的抗氧化活性低于二聚体,对于聚合体而言,原花青素对亚油酸体系和脂质体体系的抗氧化作用均随着聚合度的升高而降低。  相似文献   

3.
对葡萄籽低聚原花青素中的原花青素B2进行了分离纯化,并将葡萄籽低聚原花青素(opc’s)、原花青素B2对比白藜芦醇、红酒提取物、苹果多酚、VC、VE和水溶性V(ETrolox)的抗氧化活性进行了研究。结果表明,原花青素B2和opc’s对DPPH自由基和羟自由基都具有较好的清除活性。对DPPH自由基的清除作用与VE相当,其IC50分别为1.20μg/mL和1.39μg/mL,明显强于VC和Trolox;原花青素B2和opc’s对羟自由基的抑制率明显高于VC、VE和Trolox。opc’s经过层析分离纯化后得到的原花青素B2清除DPPH自由基的效果有所提高,但对于羟自由基的清除活性提高不明显。  相似文献   

4.
选择DPPH自由基清除体系,探讨番茄红素、葡萄籽油、VE及原花青素单独和复配后的抗氧化能力。结果显示:番茄红素、VE及原花青素的IC50值分别是7.92、44.60、14.93μg/mL,红葡萄籽油及白葡萄籽油的IC50值分别为2.54、3.77 mg/mL,表明这几种天然抗氧化剂对DPPH自由基均有明显的清除作用。并采用正交实验对以上几种抗氧化剂复配组合进行优化,确定优化配比为:番茄红素5μg/mL、葡萄籽油0.1 mg/mL、VE 25μg/mL、原花青素3μg/mL。通过计算协同系数SE,证实这几种抗氧化剂的协同作用与抗氧化剂的种类、浓度以及复配组合均显著相关,这将为复合抗氧化剂的合理使用提供理论参考。  相似文献   

5.
从菠菜叶中以硫酸铵沉降方式提取色素蛋白复合物,分析复合物中的主要功能成分,并以VC、BHT为对照,以总抗氧化能力和DPPH、·OH及O2-·等自由基的清除能力及亚油酸体系的抗氧化作用为指标,研究色素蛋白复合物的抗氧化能力及色素蛋白复合物与VC或BHT之间的相互作用.结果表明,在水相体系中复合物的总抗氧化能力为12.83 μ/mg复合物,与BHT相当,明显低于VC,当复合物浓度在10 μg/mL~500μg/mL时,对DPPH、·OH及O2-·等自由基的最大清除能力强于VC和BHT,分别为81.97%,88.14%和83.36%;以不同比例对复合物与VC或BHT进行复配,总浓度为100 μg/mL,与相同浓度色素蛋白复合物、VC或BHT单独作用时清除能力相比,发现VC与复合物之间存在协同增效作用,BHT无此效果.  相似文献   

6.
葡萄籽原花青素的分离纯化及其抗氧化活性研究   总被引:2,自引:0,他引:2  
本文以脱脂葡萄籽为原料从中提取原花青素,研究用大孔吸附树脂对原花青素分级纯化方法,以及纯化的原花青素产品清除超氧阴离子自由基、亚油酸体系的抗氧化等方面的抗氧化活性。结果显示:ADS-8大孔树脂对葡萄籽原花青素具有较强的吸附能力,得到的产物纯度达95%以上,是分离葡萄籽原花青素较理想的吸附剂;20%和40%的乙醇原花青素洗脱液具有很强的清除O2-·的能力,抑制邻苯三酚自氧化率分别达88.35%和67.2%,说明葡萄籽原花青素为抗自由基的有效活性成分;在亚油酸体系中,OPC’s的抗氧化能力高于VC和VE。  相似文献   

7.
张镜  刁树平 《食品科学》2012,33(17):101-105
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。  相似文献   

8.
山楂原花青素的抗氧化活性研究   总被引:11,自引:1,他引:11  
研究了山楂果实中的原花青素在溶液体系和脂质体体系中的体外抗氧化活性。在所用的实验模型中,山楂原花青素表现出较强的清除自由基和抑制脂质过氧化的能力。对.OH,山楂原花青素和Vc的IC50分别约为0.053mg/mL和0.11mg/mL;对O2-.,山楂原花青素和VC的IC50分别约为0.05mg/mL和0.17mg/mL。在脂质体体系中,山楂原花青素抑制脂质过氧化的能力远大于VE。  相似文献   

9.
为研究杜仲叶抗氧化成分,深入开发杜仲叶资源,测定杜仲叶水提取物及其氯仿、乙酸乙酯、正丁醇萃取物和萃余相的DPPH自由基清除活性、羟自由基清除活性、抗氧化活性、金属离子络合力和还原力,并与抗氧化剂BHT、VE以及VC的抗氧化活性比较;同时测定杜仲叶萃取物中的总酚含量。结果发现:乙酸乙酯相和正丁醇萃取物总酚含量远大于水提取物,含量依次为465.1mg/g和286.4mg/g。二者在亚油酸乳浊液中抗氧化活性高于VE,接近BHT;DPPH自由基清除活性接近VC,显著高于BHT;正丁醇萃取物对羟自由基清除活性接近VE;乙酸乙酯萃取物对三价铁离子还原力高于BHT和VC;但是所有样品对二价铁离子络合力均较低。此结果表明乙酸乙酯和正丁醇可以富集杜仲叶抗氧化成分,杜仲叶提取物具有发展为抗氧化剂的潜力。  相似文献   

10.
通过测定DPPH自由基的清除率、羟自由基的清除率、还原力以及螯合金属的能力,并与天然抗氧化剂VC、VE、儿茶素、蜂胶和合成抗氧化剂BHT、TBHQ、PG进行比较,研究葡萄籽提取物(Grape seed extract,GSE)的抗氧化活性。结果显示:GSE具有较强的DPPH自由基清除能力、还原能力和螯合金属铁离子的能力,均高于VE、蜂胶、BHT;GSE清除羟自由基的能力较弱,低于VC、VE、儿茶素、蜂胶、BHT、TBHQ。表明GSE的抗氧化机理与自由基、还原力和螯合金属离子有关。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH3CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH2PO4-20.6 mM Na2B4O7 buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.  相似文献   

16.
A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.  相似文献   

17.
An investigation is described in which various polyfunctional compounds were applied to wool in attempts to stabilize the temporary improvements in wrinkle-recovery brought about by ‘annealing’. Several reactive systems involving formaldehyde were found to produce the desired permanently improved wrinkle-recovery.  相似文献   

18.
BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H2O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.  相似文献   

19.
正As a biennial industry event,ITMA ASIA+CITME2014 has attracted leading enterprises within global textile industry from Europe,American and Japan etc..To showcase the comprehensive development of oversea enterprises,The Textile Machiney Magazine has selected representative enterprises ranging from spinning,weaving,chemical fiber,knitting,nonwovensindustrial,accessories,dyeing and printing,to exhibit their advanced technology and equipment.In the era that global textile industry have ushered a new round  相似文献   

20.
《造纸信息》2014,(8):79-79
Ministr y of Industr y and Information Technology confirmed that the main expected targets for energysaving and comprehensive utilization in 2014 are:energy consumption and CO2 emissions per unit of industrial added-value decreases by 4.5%,water consumption per ten thousand Yuan of industrial added-value decreases by7%,comprehensive utilization of industrial solid waste is further improved,and pollution emissions in key industries is markedly reduced.  相似文献   

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