沙葱不同部位提取物总黄酮含量及其体外抗氧化、抗菌活性研究

以沙葱花、叶、秆提取物为对象,研究沙葱不同部位提取物中总黄酮含量、还原能力、清除DPPH自由基能力、体外清除羟基自由基能力以及体外对大肠埃希氏菌、金黄色葡萄球菌、绿脓杆菌和沙门氏菌的抑菌作用。结果表明:沙葱不同部位提取物总黄酮含量最高的为沙葱叶提取物,且各提取物均有一定的体外抗氧化与抗菌作用,其中沙葱叶提取物体外抗氧化及抗菌活性较好,对DPPH自由基的清除率可达52.2%、对羟基自由基的清除率可达84.4%。     

明日叶的茎与叶主要抗氧化成分含量及抗氧化性比较

以明日叶茎杆与叶子为研究对象,在测定其乙醇提取物总酚酸及总黄酮含量的基础上,以芦丁为阳性对照,测定其乙醇提取物总抗氧化能力,铁离子还原/抗氧化力,以及对超氧阴离子自由基、羟基自由基、DPPH有机自由基的清除作用,并对茎杆与叶子乙醇提取物进行抗氧化活性比较。结果表明:叶乙醇提取物总酚酸和总黄酮的含量分别是茎乙醇提取物的2.2倍和5.2倍。在总黄酮质量浓度相同的条件下,叶乙醇提取物和茎乙醇提取物的抗氧化活性均与其总黄酮质量浓度呈正相关,且叶乙醇提取物的抗氧化性大于茎乙醇提取物。与芦丁相比较,芦丁对羟基自由基的清除能力大于叶乙醇提取物,其他抗氧化活性均小于叶乙醇提取物而大于茎乙醇提取物。结果表明,明日叶的叶乙醇提取物可以作为一种新型有效的天然抗氧化物质进行开发利用。     

生何首乌体外抗氧化活性及抗菌活性的研究

研究生何首乌不同提取物的体外抗氧化活性及抗菌活性。在体外化学模拟的条件下,采用比色法,测定了何首乌水提物和醇提物对DPPH自由基的还原能力及抗脂质过氧化能力,羟基自由基的清除能力以及总体抗氧化能力。同时测定了何首乌水提物和醇提物的总酚酸和总黄酮的含量。利用滤纸片扩散法测定了何首乌水提物和醇提物对6种微生物的抗菌活性。何首乌醇提物的体外抗氧化活性强于水提物,具有显著的DPPH自由基和羟基自由基清除能力和较强的抗脂质过氧化能力,具有一定的还原能力,其总体抗氧化能力也比较强。何首乌水提取物和醇提取物的总酚酸和总黄酮含量分别126.52、77.25μg/mg和153.04、126.11μg/mg。另外何首乌的醇提物对金黄色葡萄球菌、四联球菌和大肠杆菌显示出较强的抑制活性,水提物对金黄色葡萄球菌和荧光假单胞菌显示出一定的抑菌活性。何首乌具有强的抗氧化活性与一定的抗菌活性。     

箬叶总黄酮体外抗氧化活性的研究

考察了超声波法提取的箬叶总黄酮的体外抗氧化活性,研究了箬叶总黄酮对ABTs、DPPH自由基、羟基自由基、亚硝基自由基、超氧阴离子自由基的清除能力,并以常用的抗氧化剂Vc和芦丁作为对照品进行比较。实验表明,对于ABTs、DPPH自由基,箬叶总黄酮的清除率明显高于Vc和芦丁,其IC_(50)为Vc和芦丁的1/2~1/7;对于羟基、亚硝基自由基,在浓度相对较低时,箬叶总黄酮的清除自由基能力与Vc和芦丁相当,当浓度增加80μg/m L,箬叶总黄酮的清除自由基能力明显强于Vc和芦丁;但对超氧阴离子自由基,箬叶黄酮提取物清除率低于Vc对照品。箬叶总黄酮提取物大多表现出强于Vc和芦丁的体外抗氧化活性,作为天然抗氧化剂具有较好的应用前景。     

不同蕨菜制品醇提物体外抗氧化及降血糖活性研究

目的:比较研究不同蕨菜制品醇提取物的体外抗氧化和降血糖活性。方法:分别采用Folin-Ciocalteu法、NaNO₂ -Al（NO₃）₃法测定总酚和总黄酮含量;通过DPPH法、ABTS法、普鲁士蓝法、α-葡萄糖苷酶和α-淀粉酶的抑制活性评价体外抗氧化、降血糖活性;Pearson法分析成分含量与活性的相关性。结果:不同蕨菜醇提物的总酚和总黄酮含量、抗氧化活性、α-葡萄糖苷酶和α-淀粉酶抑制活性差异显著。其中鲜品醇提取物的总酚、总黄酮含量最高,分别可达（593±3.45）mg GA/g、（156.75±1.28）mg RT/g,且鲜品醇提取物铁离子还原能力、ABTS自由基清除能力、DPPH自由基清除能力最强;湿品醇提取物对α-葡萄糖苷酶、α-淀粉酶的抑制作用最强。不同蕨菜醇提取物总酚、总黄酮的含量与其抗氧化活性均呈极显著正相关关系（P<0.01）,与降血糖活性均呈显著正相关关系（P<0.05）。结论:蕨菜鲜品抗氧化活性较强,湿品降血糖活性较强,可能活性成分为多酚类和黄酮类成分。     

准噶尔山楂叶抗氧化及抑制α-葡萄糖苷酶活性

采用超声提取不同月份准噶尔山楂叶,系统溶剂萃取其醇提物得到环己烷部位、乙酸乙酯部位、正丁醇部位和水部位,分别测定其总黄酮含量,通过清除DPPH自由基、铁离子还原能力和α-葡萄糖苷酶抑制活性评价准噶尔山楂叶不同提取物的体外抗氧化活性及降血糖活性。结果表明,准噶尔山楂叶各提取物均有不同程度的抗氧化和α-葡萄糖苷酶抑制活性,其中以总黄酮含量最高的乙酸乙酯部位(28.87 mg/g)效果最佳,其对DPPH清除活性(IC_(50)=0.026 mg/m L)远强于阳性对照BHA(IC_(50)=0.996 mg/m L),α-葡萄糖苷酶抑制活性(IC_(50)=191.71 g/m L)高于阳性对照阿卡波糖(IC_(50)=1 044.32 g/m L)。各提取物体外抗氧化和降血糖活性与其总黄酮含量呈正相关性,说明黄酮类化合物为影响其活性的主要因素。     

辣椒叶多酚抗氧化及抗炎活性研究

通过ABTS+自由基、DPPH自由基清除能力、铁还原能力、小鼠耳肿胀实验考查辣椒叶多酚提取物粗提物及纯化物的体外抗氧化及抗急性炎症活性.结果表明,辣椒叶多酚提取物具有一定的抗氧化能力,其纯化物清除ABTS+自由基、DPPH自由基和铁还原能力的IC50分别为0.700、0.643、0.758mg/mL,与对照品VC浓度处于同一数量级,说明辣椒叶多酚提取物是一种有效的天然抗氧化剂;600mg/kg剂量的辣椒叶多酚的粗提物及纯化物,均对二甲苯所致小鼠耳肿胀有极显著抑制作用,抑制率分别为59.84％、62.69％(p＜0.01);炎症组织PGE2含量从32.41A/g可分别降至19.27、16.51A/g(p ＜0.05);实验小鼠血清肝损伤指标ALT(谷丙转氨酶)和AST(谷草转氨酶)的监测表明辣椒叶多酚提取物具有较高安全性.实验结果表明辣椒叶多酚提取物具有一定的抗氧化及抗急性炎症活性且安全性较高,为进一步开发利用辣椒资源提供了理论依据.     

芦蒿不同部位清除自由基活性研究

考察芦蒿中不同部位活性成分的提取及其抗氧化清除自由基的性能。芦蒿的秸秆、花、叶、茎经过粉碎,烘干,石油醚脱色后,用60%的乙醇为提取剂提取活性成分,通过定性定量试验测定黄酮类化合物的含量,并对照抗坏血酸探讨了芦蒿不同部位醇提物的抗氧化活性,包括还原能力,螯合能力以及清除DPPH自由基、清除羟基自由基、清除超氧阴离子能力。结果表明:芦蒿各部位提取物其抗氧化清除自由基由强到弱排序为叶提取物>花提取物>茎提取物>秸秆提取物;对自由基清除能力排序分别为超氧阴离子、DPPH、羟自由基。芦蒿各部位提取物均具有还原性,抗氧化及清除不同自由基性能。     

覆盆子不同极性溶剂提取物的抗氧化活性比较

为比较覆盆子不同极性溶剂提取物的抗氧化活性,分别用正丁醇、乙酸乙酯、丙酮、去离子水、50％乙醇和石油醚进行萃取,测定各提取物总多酚和总黄酮的含量,并通过清除DPPH自由基、ABTS自由基、羟基自由基和总还原能力4种体系对其体外抗氧化活性进行评价.结果显示,乙酸乙酯提取物中总多酚含量最高,50％乙醇提取物中总黄酮含量最高...     

青钱柳提取物体外抗氧化活性研究

研究青钱柳不同溶剂提取物的体外抗氧化活性。测定了青钱柳不同溶剂提取物对DPPH自由基的清除作用,用化学发光法测定对超氧阴离子自由基(O·2)和羟自由基(·OH)的清除能力,并用烘箱储藏法测定对油脂的抗氧化活性。实验结果表明,醇提物具有较强的清除自由基能力和抗油脂氧化活性。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

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.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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