基于“成分-抗氧化”关联的朝鲜蓟不同部位比较研究

基于"成分-抗氧化"的关联模式,测定朝鲜蓟叶片、叶梗及花苞3个部位活性成分,并以DPPH·、ABTS⁺·和·OH清除率为抗氧化功能评价指标,比较各部位抗氧化能力,综合分析各类成分含量与抗氧化功能之间的相关性。结果表明:总多酚和总黄酮含量以及DPPH·、ABTS⁺·清除率大小为叶片>花苞>叶梗,总多糖含量大小为花苞>叶梗>叶片,游离氨基酸含量及·OH清除率大小为叶片>叶梗>花苞。DPPH·、ABTS⁺·清除能力和总多酚、总黄酮含量呈较强的正相关性,可为朝鲜蓟药用资源的深入开发和利用提供一定的理论依据。     

草果不同低共熔溶剂提取物活性成分与其抗氧化活性的相关性分析

以草果为原料,测定5种不同低共熔溶剂提取物中总黄酮和总多酚含量,通过总还原能力及对DPPH·、ABTS⁺·、·OH、NO₂^-清除能力评价其抗氧化活性,并探讨总黄酮和总多酚与抗氧化能力的相关性。结果表明氯化胆碱—乙二醇低共熔溶剂草果提取物总黄酮含量最高,氯化胆碱—草酸低共熔溶剂草果提取物总多酚含量最高,不同低共熔溶剂提取物均有抗氧化活性,草果提取物中总多酚与ABTS⁺自由基清除率、羟基自由基清除率和NO₂^-清除率呈显著相关,为草果的高效利用提供依据。     

不同产地香椿嫩芽主要营养成分、活性物质及挥发性成分分析

为分析比较不同产地香椿嫩芽的品质差异和加工适用性,以6个产地来源的红油香椿为研究对象,采用常规理化方法测定香椿嫩芽中可溶性蛋白、维生素C(V_C)、总黄酮、总生物碱、总多糖、总多酚、总皂苷含量,采用顶空固相微萃取以及气相色谱-质谱联用技术分析鉴定香椿嫩芽的挥发性成分。结果表明:6个产地中,山东淄博香椿嫩芽中可溶性蛋白含量最高,达0.74%;河南桐柏香椿嫩芽中的V_C含量最高,达0.83%,与其他产地差异显著(p<0.05);山西永济香椿嫩芽的总黄酮、总生物碱、总多糖、总多酚和总皂苷含量均明显高于其他产地。6个产地香椿嫩芽共检出87种挥发性物质,其中河南新乡检出16种,河南桐柏33种,山西永济29种,山东淄博28种,陕西安康33种,湖北十堰陆35种,6个产地香椿嫩芽共检出6种共有化合物,分别为2-己烯醛、β-环柠檬醛、2,4-二甲基噻吩、2-巯基-2,3-二氢-3,4-二甲基噻吩、古巴烯和[1R-(1R*,4Z,9S*)]-4,11,11-4,11,11-三甲基-8-亚甲基-二环[7.2.0]十一碳-4-烯。不同产地相对含量较高的为萜烯类、醛类和含硫类物质,且检出种类最多的均为萜烯类物质。综合分析山西永济香椿品质较为优良,不同产地香椿营养成分、活性物质及挥发性成分呈现出产地差异性,可根据产品加工需求选择原料产地。     

茶枝柑果肉发酵过程中感官特性及抗氧化活性的变化

本文旨在研究酵母发酵茶枝柑果汁过程中感官、化学成分和抗氧化活性的变化,促进茶质柑果肉资源的合理利用。从组织状态、色泽、酸味、甜味、苦涩、香气六个方面评价其感官特性;测定发酵过程中总酸、还原糖、总酚、总黄酮的含量;通过GC-MS检测其香气成分及相对含量;结合DPPH·清除率和·OH清除率评价其抗氧化活性。研究表明,采用0.5%接种量接种安琪酵母,40 ℃发酵96 h后的茶枝柑发酵果汁口感酸甜适中,苦涩感较弱,带有果香味和发酵风味;挥发性香味物质经0~96 h发酵,烯烃含量最高由53.70%增加至77.77%,主要成分为d-柠檬烯和γ-萜烯;其次是醇类由34.50%降至16.05%,酯类由7.74%降至2.44%;醛酮与酚类含量较少(<1%)。发酵过程中总酸、还原糖含量逐渐减少,总酚、总黄酮含量先大幅减少后略有增加;发酵过程中DPPH·清除率逐渐降低,与总酚、总黄酮、总酸及还原糖含量均呈显著相关(P<0.05);·OH清除率逐渐降低,与总酸含量呈极显著相关(P<0.01),与总黄酮含量和还原糖含量呈显著相关(P<0.05);·OH清除率与总酚含量无显著相关性(P>0.05)。     

五个产地荔枝核中药饮片抗氧化活性研究

为了比较五个产地荔枝核中药饮片的体外抗氧化活性,分别采用DPPH法、ABTS法和总抗氧化能力测试法(T-AOC)对5个产地荔枝核的90%乙醇提取物进行抗氧化活性测定,同时对其中的活性成分包括多酚、黄酮和皂苷及其含量与抗氧化活性的相关性进行了初步分析。结果表明:广东惠东荔枝核中多酚和黄酮含量最高,其次为阳西荔枝核,广西灵山荔枝核多酚和黄酮含量均最低;阳西荔枝核中皂苷含量最高,其他产地皂苷含量从高到低依次为广东惠东、从化、东莞和广西灵山。各产地荔枝核提取液对DPPH自由基的清除率差异均不显著,而对ABTS+自由基的清除率差异显著,其中广东阳西荔枝核的清除能力最强,总抗氧化能力测定结果表明广东从化荔枝核抗氧化能力最强,广西灵山荔枝核最弱。活性物质与抗氧化活性相关性分析表明多酚、黄酮和皂苷均与抗氧化活性呈现一定的正相关。     

3种野生浆果果酒中活性物质及抗氧化活性比较

研究了白刺、沙棘、黑枸杞发酵果酒中黄酮、多酚、多糖、原花青素、花色苷的含量及其对铁离子的还原力和亚油酸脂质过氧化的抑制效果,采用DPPH、ABTS、H2O2/Fe2+/水杨酸、超氧阴离子自由基清除体系考察了3种果酒的抗氧化能力,并对活性成分含量与抗氧化活性进行了相关性分析。结果表明,沙棘酒中多糖含量最高,为0.605 mg/m L,其对·OH的清除率最高,为97.98%;黒枸杞酒中花色苷含量最高,为0.245 mg/m L,其对DPPH·的清除率最好,为97.14%,对铁离子的还原能力最高为11.29 mg/m L;白刺酒对O2-·的清除率最高为90.93%。对活性成分含量与抗氧化活性相关性分析表明,果酒对DPPH·的清除作用与酒中花色苷的含量呈正相关;果酒中多糖含量对·OH的清除呈正相关而对DPPH·的清除呈负相关;果酒中黄酮、多酚和原花青素含量与ABTS·及亚油酸过氧化的抑制呈正相关,与O2-·的清除率呈负相关。     

不同品种薯尖的总酚、总黄酮含量及抗氧化活性比较

为筛选出抗氧化活性较高的薯尖品种、为薯尖的开发利用提供理论依据,本研究比较了四种不同品种薯尖(福薯7-6、福薯18、宁菜、7001)的叶、茎尖、柄、茎4个部位的总酚、总黄酮含量。并且以DPPH·清除率、总还原力、·OH清除能力、超氧阴离子自由基清除能力为抗氧化活性衡量指标,分析了4个品种各个部位的抗氧化活性及其与酚类物质含量的相关性。实验表明:4种薯尖的总多酚含量介于4.42~98.15 mg GAE/g DW,总黄酮含量介于0.97~36.17mg RE/g DW,DPPH·清除率介于5.13~53.1 mg trolox/g,总还原力介于5.65~115.00 mg Vc/g,·OH清除能力介于0.04~0.06(Vc mg/g),超氧阴离子清除能力介于27.11%~54.50%;在4个部位间,叶、茎尖的酚类物质含量及相关抗氧化活性总体上显著高于其他部位;4种薯尖中只有福薯7-6和福薯18在叶部位的总黄酮含量无显著差异,且各个品种在茎尖和柄部位的·OH清除能力均无显著差异;总酚、总黄酮含量与抗氧化活性均呈正相关。总而言之,不同品种、不同部位薯尖的总酚、总黄酮含量,以及其抗氧化活性均存在一定差异。经过筛选认为7001品种薯尖的酚类物质含量及其抗氧化能力最高,可作为优质抗氧化剂的资源。     

金银花不同提取物抗氧化活性的研究

初步研究金银花不同提取物的抗氧化活性。将金银花药材用石油醚脱脂后,分别用无水乙醇、95%乙醇、90%乙醇、80%乙醇、70%乙醇、60%乙醇和50%乙醇提取,采用紫外-可见分光光度法对不同溶剂提取物的绿原酸、总黄酮和总酚含量进行分析,并测试各提取物对羟基自由基(·OH)和二苯代苦味酰基自由基(DPPH·)的清除作用以对其抗氧化活性进行比较。结果表明:金银花95%乙醇提取物绿原酸、总黄酮和总酚含量最高,分别为123.99、242.62和48.76 mg/g;95%乙醇提取物清除·OH和DPPH·能力也最强,清除率分别为90.69%和65.64%。可见,金银花清除·OH和DPPH·自由基的能力与绿原酸、黄酮和多酚的含量具有一定的相关性。     

多花黄精非药用部位活性成分及抗氧化性比较

目的:提高多花黄精的综合利用。方法:测定多花黄精根、茎、叶、花和嫩芽5个非药用部位的总黄酮、总皂苷和总酚含量,并比较非药用部位提取液的DPPH·、·OH及对亚硝酸盐的清除率。结果:多花黄精5个部位中总黄酮和总酚含量顺序大小一致,依次为叶>嫩芽>花>茎>根,总皂苷以花中含量最高;抗氧化活性方面,叶提取液的DPPH·、·OH和对亚硝酸盐的清除率最高,其次是嫩芽、花。相关性分析发现,多花黄精非药用部位提取液对DPPH·、·OH和亚硝酸盐的清除率与总黄酮、总皂苷和总酚含量均表现出一定的正相关。结论:多花黄精非药用部位提取液具有较好的生物活性。     

红枣可溶性膳食纤维的抗氧化活性研究

为研究红枣可溶性膳食纤维(Soluble Dietary Fiber,SDF)的体外抗氧化活性,采用Na NO_2-Al(NO_3)_3-Na OH法和Folin-Ciocalteu法分别测定红枣SDF中总黄酮和总多酚含量,并通过DPPH·、ABTS~+·、·OH、O_2~-·和H_2O_2自由基清除体系和还原能力评价红枣SDF的抗氧化活性。结果表明:红枣SDF中总黄酮和总多酚含量分别为(1.78±0.04)mg/g和(4.12±0.09)mg/g;红枣SDF具有较强的体外抗氧化活性,对DPPH·和H_2O_2清除能力较强,2.0 mg/m L红枣SDF的清除率分别可达到79.81%和50.07%,尤其对DPPH·的清除能力最强,其半数抑制浓度(IC_(50))为0.725 mg/m L,对ABTS~+·、·OH、O_2~-·的清除能力较弱,并具有一定还原能力。红枣SDF具有一定的体外抗氧化活性,可作为一种有效的天然食品抗氧化剂或用于开发红枣膳食纤维功能性食品。     

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