蛹虫草胞外锌多糖抗氧化能力的研究

以蛹虫草为材料通过液体深层富锌培养获得胞外富锌多糖,测定了蛹虫草胞外富锌多糖的锌含量和抗氧化性能,即清除氧自由基、羟自由基和DPPH的能力。实验结果表明:蛹虫草富锌培养基内ZnSO4浓度在150μg/mL下,可以显著提高胞外锌多糖的有机锌含量(P<0.01),使有机锌含量达到0.87mg/g,比对照提高295%。有机锌对提高胞外锌多糖清除自由基的能力有显著的促进作用(P<0.01),清除氧自由基、羟自由基和DPPH的能力分别是对照的7.05%、23.5%和17.49%;胞外锌多糖对自由基的清除能力与多糖浓度呈明显的剂量-效应关系(P<0.01)。     

树舌胞内多糖抗氧化活性的研究

目的:探讨树舌胞内多糖(GAPS)体外抗氧化作用.方法:从清除超氧阴离子自由基、抑制羟基自由基的产生、清除DPPH自由基和还原力4个方面,研究了树舌胞内多糖的体外抗氧化效果.结果:树舌胞内多糖有较强的还原力,并在体外对超氧阴离子自由基(O-2·)、羟基自由基(·OH)、DPPH有机自由基有较强的清除作用.树舌胞内多糖浓度为1.0mg/mL时,其清除O-2·能力为36.36%;对于·OH,在浓度为2.5mg/mL时,清除率达到56.97%;对于DPPH·,在浓度为1.0mg/mL时,清除率达到45.31%;当树舌胞内多糖浓度为0.5mg/mL时的还原能力与0.03mg/mLVc,相当.结论:树舌胞内多糖具有抗氧化方面的应用开发前景.     

树舌富锗深层培养研究

研究了不同浓度的锗对树舌液体培养生物量、菌丝体中有机锗、胞内多糖、腺苷及胞外多糖等主要活性成分含量的影响。结果表明,锗浓度在50~250μg/mL的范围内,对树舌菌丝体主要活性成分合成有很好促进作用,在锗浓度为250μg/mL时,生物量、有机锗、胞内多糖、腺苷均达最高,分别为15.44g/L、588μg/g、24.88mg/g、1.41mg/g,分别比对照组提高了33.1%、1267.4%、73.9%、101.4%。胞外多糖含量在锗浓度为150μg/mL时达到1.12g/L,比对照组提高了31.7%。     

高良姜多糖提取工艺优化及其抗氧化活性研究

通过Box-Behnken试验设计,获得了热水浸提高良姜多糖的最佳工艺;以清除1,1-二苯基-2-三硝基苯肼（DPPH）自由基能力、还原力、清除羟自由基能力、螯合铁离子能力为指标,评价了高良姜多糖的抗氧化活性。结果表明,热水浸提高良姜多糖的最佳工艺条件为液料比43∶1（mL/g）、浸提温度95 ℃、浸提时间3 h,在此条件下多糖得率实测值为11.81%。高良姜多糖具有较好的抗氧化活性,清除自由基能力、还原力和螯合铁离子能力均表现出一定的质量浓度依赖性;高良姜多糖清除DPPH自由基、清除羟自由基和螯合铁离子能力的半数有效质量浓度（EC50）分别为（0.59±0.01）、（0.05±0.003）g/L和（2.75±0.2）g/L。     

高良姜多糖提取工艺优化及其抗氧化活性

通过Box-Behnken试验设计,获得了热水浸提高良姜多糖的最佳工艺;以清除1,1-二苯基-2-三硝基苯肼(DPPH)自由基能力、还原力、清除羟自由基能力、螯合铁离子能力为指标,评价了高良姜多糖的抗氧化活性。结果表明,热水浸提高良姜多糖的最佳工艺条件为液料比43∶1(mL/g)、浸提温度95℃、浸提时间3 h,在此条件下多糖得率实测值为11.81%。高良姜多糖具有较好的抗氧化活性,清除自由基能力、还原力和螯合铁离子能力均表现出一定的质量浓度依赖性;高良姜多糖清除DPPH自由基、清除羟自由基和螯合铁离子能力的半数有效质量浓度(EC50)分别为(0.59±0.01)、(0.05±0.003)g/L和(2.75±0.2)g/L。     

响应面优化超声提取黑果腺肋花楸叶多糖工艺及抗氧化研究

通过响应面试验设计,获得超声提取黑果腺肋花楸叶多糖的最佳工艺条件,通过TCA法将粗多糖中的蛋白成分除去后得到精制多糖;以清除铁还原力、1,1-二苯基-2-三硝基苯肼(DPPH)自由基能力和清除羟自由基能力为指标,评价黑果腺肋花楸叶多糖的抗氧化活性。结果表明,超声提取黑果腺肋花楸叶多糖的最佳工艺条件为:超声温度67℃,超声时间53 min,超声功率150W,料液比1∶30(g∶mL)在此条件下多糖得率为5.01%。黑果腺肋花楸叶多糖具有较好的抗氧化活性,铁还原力、清除DPPH自由基能力和清除羟自由基能力均表现出一定的质量浓度依赖性;黑果腺肋花楸叶多糖多糖铁还原力、清除DPPH自由基和清除羟自由基能力的半数有效质量浓度(EC50)分别为0.623g/L、0.473g/L和0.147g/L。     

苜蓿、黄芪、地衣芽孢杆菌胞外多糖体外抗氧化活性研究

通过1,1-二苯基-2-苦基苯肼(DPPH)自由基和羟自由基的清除实验研究了苜蓿多糖、黄芪多糖和地衣芽孢杆菌TS-01胞外多糖对自由基的清除能力并比较了三者的清除效果。结果表明:三种多糖均具有清除DPPH·及羟自由基的作用,并且随着多糖浓度的增加,清除DPPH·和羟自由基的能力也逐渐增强,呈现明显的剂量-效应关系。苜蓿多糖、黄芪多糖和地衣芽孢杆菌TS-01胞外多糖对DPPH自由基的清除率达50%时所需多糖浓度(IC50)分别为:0.251、0.851、0.412mg/mL,即清除DPPH自由基的能力由强到弱依次为:苜蓿多糖>胞外多糖>黄芪多糖。对于羟自由基,三种多糖的IC50分别为:0.573、0.907、0.734mg/mL,三者清除羟自由基能力的强弱顺序与对DPPH·的清除一致。     

酸肉肽抗氧化活性的研究

通过测定酸肉肽对DPPH 自由基、羟自由基、亚硝酸盐的清除能力及其还原能力,研究其抗氧化活性。结果：酸肉肽对DPPH 自由基有良好的清除能力,IC50 值为247.96μg/mL,是BHT 的4.97 倍;酸肉肽具有显著的清除羟自由基能力,IC50 值为33.60μg/mL,是BHT 的1.52 倍;酸肉肽的还原能力较强,约为BHT 的0.25 倍;酸肉肽对亚硝酸盐具有一定的清除作用。实验表明酸肉肽具有明显的抗氧化效果。     

酶解-超声协同提取茄蒂多糖及抗氧化研究

以茄蒂为原料,研究了酶解超声协同提取茄蒂多糖条件及抗氧化能力。在pH5、50℃水浴温度下用1%纤维素酶酶解30min,采用响应面法优化超声提取茄蒂多糖条件。通过测定对羟自由基、超氧自由基清除能力和总还原力,评价茄蒂多糖抗氧化活性。结果表明,茄蒂多糖最佳提取条件为:料液比1∶36(g/mL),超声时间22min,超声温度68℃。在此条件下多糖得率为5.49%。茄蒂多糖对羟自由基、超氧自由基清除能力和还原力均表现较好的效果,其清除羟自由基、超氧自由基的IC50值分别为0.12、0.22mg/mL。茄蒂多糖抗氧化性略低于VC。     

紫色马铃薯花色苷抗氧化活性研究

从紫色马铃薯中提取出花色苷,对其抗氧化活性进行了研究。对紫色马铃薯花色苷的总还原力、清除DPPH·、抗脂体抗氧化活性和清除羟自由基能力的试验结果表明:紫色马铃薯花色苷的总还原力与抗坏血酸相当;当紫色马铃薯花色苷浓度达500μg/mL时,抗脂体抗氧化活性的抑制率为88.34%,DPPH·清除能力达到94.98%。紫色马铃薯花色苷浓度在低于400μg/mL时清除羟自由基能力的明显高于抗坏血酸,当高于400μg/mL时清除羟自由基能力低于抗坏血酸。     

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