元蘑醇提物不同极性部位有效成分含量及清除自由基活性

为了确定元蘑抗氧化活性的有效部位,采用系统溶剂法对元蘑醇提物不同极性部位成分含量及清除自由基活性进行研究。结果表明:元蘑醇提物不同极性中总酚(307.00 mg GAE/g DM)、总黄酮(625.98 mg RET/g DM)和腺苷(3.985 mg/100 g)含量最高的部位分别是乙酸乙酯相、正己烷相和正丁醇相;正己烷相具有最好的总抗氧化能力和总还原能力;正丁醇相具有最强的清除DPPH·、和ABTS~+·的能力;水相具有最强的清除羟自由基能力。元蘑不同极性具有较好的抗氧化活性,正丁醇相和乙酸乙酯相为元蘑抗氧化的有效部位。     

不结球白菜体外抗氧化活性部位的筛选与研究

应用DPPH自由基清除法、羟自由基清除法、超氧阴离子自由基清除法、ABTS+·清除法四个抗氧化指标对不结球白菜的5个不同极性部位石油醚相、氯仿相、乙酸乙酯相、正丁醇相和水相的抗氧化能力进行评价,同时考察了总酚和总黄酮的含量与抗氧化能力的关系,并对活性最强部位进行了脂质抗氧化研究。结果表明,除水相外,不结球白菜其他4个极性部位均表现出一定的抗氧化能力。总酚和总黄酮的含量与各部位的抗氧化能力具有显著相关性。乙酸乙酯相清除DPPH自由基、羟自由基、超氧阴离子自由基、ABTS+·的EC50值分别为(0.64±0.05)、(1.17±0.12)、(1.02±0.15)、(0.78±0.07)mg/m L;乙酸乙酯相的抗氧化能力最高,其总酚的含量为(151.32±1.87)mg GAE/g DW,总黄酮含量为(32.97±0.56)mg rutin/g DW;10 mg/m L的乙酸乙酯相对H2O2诱导红细胞氧化的抑制率达到62.11%,对H2O2诱导小鼠肝脏脂质过氧化的抑制率为51.26%。实验结果表明,不结球白菜乙酸乙酯相具有较强的抗氧化活性,是天然抗氧化活性物质的良好来源。     

藏茜草不同溶剂提取物的抗氧化活性研究

采用DPPH自由基清除法、ABTS自由基清除法、羟自由基清除法、超氧阴离子清除法、还原力测定法和螯合力测定法六种抗氧化模型对藏茜草95%乙醇提取物以及石油醚相,乙酸乙酯相,正丁醇相和水相等4个不同极性部位的抗氧化活性进行评价,同时分析抗氧化活性与总酚和总黄酮含量的关系。研究结果表明,除水提部位外,藏茜草其它4个极性部位提取物均表现出一定的抗氧化活性,其抗氧化活性与多酚和总黄酮含量呈显著相关。其中,乙酸乙酯部位总黄酮和总多酚含量最高,抗氧化活性也最强,其总黄酮和总多酚含量分别为(232.03±1.74)mg芦丁当量/g提取物和(173.53±1.75)mg没食子酸当量/g提取物,其清除DPPH自由基、超氧阴离子、羟自由基和ABTS自由基的EC50分别为0.06±0.01、0.17±0.01、(0.24±0.02)mg/m L和(1.75±0.23)μg/m L,对金属离子螯合力的EC50为(0.11±0.01)mg/m L。藏茜草的乙酸乙酯极性部位具有显著的抗氧化活性,是天然抗氧化活性化合物的良好来源。     

豆腐柴提取物不同极性部位的总酚、总黄酮含量及体外抗氧化活性

目的:研究豆腐柴提取物不同极性部位的体外抗氧化活性。方法:用甲醇提取豆腐柴减压浓缩后得豆腐柴提取物,依次用石油醚、三氯甲烷、乙酸乙酯、正丁醇萃取,得包括水相的五个不同极性部位,测定各极性部位的总多酚、总黄酮含量,比较各极性部位清除DPPH、ABTS、FRAP自由基的能力。结果:豆腐柴提取物的不同极性部位中乙酸乙酯相的总酚、总黄酮含量最高(总酚含量(635.935±6.529)mg GAE·g~(-1),总黄酮含量(953.018±21.774)mg QE·g~(-1)),各极性部位均提示有一定的抗氧化活性,且自由基清除力在一定范围呈显著的剂量效应关系,乙酸乙酯相与石油醚相、水相的抗氧化能力差异性较大(p0.01)。结论:豆腐柴提取物各极性部位都具有一定的抗氧化活性,可能与总酚、总黄酮含量有关,乙酸乙酯相抗氧化活性强于VC,可重点对该极性部位进一步分离纯化。     

百香果叶提取物的体外抗氧化活性和抑制α-葡萄糖苷酶的作用

为了对百香果叶进行初步活性评价,研究了其醇提物不同溶剂(石油醚、乙酸乙酯、正丁醇、水)萃取物中的总多酚、总黄酮含量,抗氧化活性和α-葡萄糖苷酶抑制性,及其之间的相关性。结果发现,乙酸乙酯萃取物的多酚和黄酮含量最高,分别为(57.0±1.2)mg没食子酸/g和(70.8±1.6)mg芦丁/g。4种萃取物都具有一定的抗氧化性和抑制α-葡萄糖苷酶的作用,尤其是乙酸乙酯和正丁醇萃取物对DPPH自由基的清除作用强于对照品BHT。相关性分析结果表明,清除羟自由基的能力与总酚和总黄酮含量的相关性不高,r分别为0.546和0.540;另外3个模型的抗氧化活性与总酚和总黄酮含量的相关性较大(0.788r0.847);而α-葡萄糖苷酶抑制率与总酚和总黄酮含量的相关性为极显著(P0.01)。比较发现百香果叶醇提物的乙酸乙酯萃取物抗氧化活性和抑制α-葡萄糖苷酶的作用最强,是天然抗氧化剂的良好来源。     

覆盆子醇提物及其不同极性部位抗氧化活性研究

以覆盆子醇提物及其不同极性部位的总酚、黄酮含量和抗氧化活性为研究目的,采用还原力,1,1-二苯基-2-苦基肼(DPPH)和OH自由基清除能力抗氧化体系来评价它们的抗氧化活性,研究结果表明:乙酸乙酯相的总酚和黄酮含量最高,分别为(328.33±13.75)mg/g和(298.25±25.64)mg/g(p<0.05);该相在不同抗氧化体系中的抗氧化活性也最强,清除DPPH和OH的能力显著强于BHT(p<0.05)。覆盆子醇提物及其不同极性部位中的总酚含量与还原力,DPPH和OH清除能力呈正相关,相关系数分别为0.9197、0.9321和0.9808,这表明总酚是覆盆子提取物的主要抗氧化活性成分。     

红海榄不同部位总酚和总黄酮含量分析及抗氧化活性研究

研究红海榄(Rhizophora stylosa)根、茎、叶、花4个部位的总酚、总黄酮含量及其抗氧化能力,结果表明:红海榄茎部的总酚和总黄酮含量最高,分别为(16.91±0.23)、(38.99±1.86)mg/g;红海榄植物各部位中茎的提取物清除DPPH(1,1-二苯基-2-三硝基苯肼)自由基和ABTS[2,2’-连氮基-双-(3-乙基苯并二氢噻唑啉-6-磺酸)]自由基能力最强,IC50值分别为(0.351±0.02)、(0.348±0.01)mg/mL。总酚含量、总黄酮含量与抗氧化能力之间相关性分析表明,总黄酮与抗氧化能力之间存在正相关,与清除DPPH自由基能力相关系数R达到0.957,与清除ABTS自由基能力相关系数R为0.772,表明黄酮类物质是其抗氧化作用的主要物质基础。     

青钱柳叶活性成分的抗氧化活性及UPLC-QTOF-MS/MS分析

利用96孔板法测定青钱柳叶不同溶剂(水、70%乙醇、乙酸乙酯和正己烷)提取物中总酚、总黄酮含量及抗氧化活性(DPPH自由基清除能力、还原能力、总抗氧化能力),考察酚类物质含量与抗氧化活性的相关性,并采用超高效液相色谱-四极杆飞行时间串联质谱(ultra performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spetrometry,UPLC-QTOF-MS/MS)分析提取物中主要活性成分。结果表明:不同提取物中总酚、总黄酮含量及抗氧化活性存在显著性差异且70%乙醇溶液提取物表现出最高的总酚(219.01 mg GAE/g)、总黄酮含量(7.23 mg CE/g)及最强的DPPH自由基清除能力(35.46 mg TE/g)和还原能力(1.89 mmol Fe SO_4/g);总酚、总黄酮含量与DPPH自由基清除能力、还原能力之间呈正相关,与总抗氧化能力呈显著负相关,表明多酚类物质是青钱柳中主要的抗氧化剂。UPLC-QTOF-MS/MS分析70%乙醇溶液提取物并初步鉴定出22种化合物,包括2种有机酸、4种酚酸、5种黄酮、8种三萜皂苷类和3种酯类,其中酚酸和黄酮类化合物是主要的抗氧化活性成分,有机酸、三萜皂苷及酯类化合物可能是潜在的抗氧化活性成分。     

厚朴籽不同溶剂萃取物抗氧化活性比较分析

为研究厚朴籽抗氧化成分,测定厚朴籽90%乙醇粗提物及其石油醚、乙酸乙酯、正丁醇和水萃取物的1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除活性,2,2-联氮基-双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐(2,2-azino-bis(3-ethylbenzthiazoline-6-sulonic acid),ABTS)自由基清除活性和铁离子还原能力(ferric reducing antioxidant power,FRAP),同时测定其总酚及总黄酮含量。结果发现,乙酸乙酯萃取物的总酚和总黄酮的含量最高,含量依次为(253.64±7.25)和(179.11±0.61)mg/g。厚朴籽乙醇粗提物和萃取物具有一定抗氧化活性,其中乙酸乙酯萃取物的抗氧化活性最强,DPPH自由基清除活性显著(P<0.05)高于阳性对照BHT,其IC₅₀仅为(29.33±2.31)μg/mL;乙酸乙酯萃取物ABTS自由基清除活性与V_C相当,IC₅₀分别(30.33±1.53)和(31.67±3.06)μg/mL;厚朴籽乙醇粗提物和萃取物对铁离子的还原能力较低,均显著(P<0.05)低于阳性对照V_C和BHT。相关性显示,厚朴籽三种体外抗氧化活性均与总酚和总黄酮极显著相关(P<0.01)。以上结果表明,乙酸乙酯可以富集厚朴籽酚类物质,为下一步厚朴籽抗氧化物质分离奠定了理论依据。     

苦荞麸乙醇粗提物各极性成分的抗氧化活性研究

目的:寻找苦荞麸乙醇粗提物中抗氧化活性最强的部分,为分离该部分的有效成分提供参考.方法:以营荞麸为原料,用95％乙醇提取苦荞麸总黄酮粗提物;水悬浮,乙酸乙酯、正丁醇萃取,测定各萃取相以及苦荞麸总黄酮粗提物的总酚和总黄酮含量;通过DPPH·的清除能力、ABTS·+的清除能力、总还原力以及抑制β-胡萝卜素褪色能力的测定,比较不同萃取相和粗提物的抗氧化性.结果:乙酸乙酯相的总酚和总黄酮含量最高,抗氧化活性最强.乙酸乙酯萃取物的DPPH·清除能力(EC5078.86 μg/mL)优于芦丁(EC50135.71 μg/mL),弱于VC(EC5071.26 μg/mL);ABTS·+清除能力(EC5029.79 μg/mL)优于芦丁(EC5072.96 μg/mL)和VC (EC50112.71 μg/mL),还原力高于芦丁和槲皮素,抑制β-胡萝卜素褪色的能力(EC50101.24 μg/mL)低于BHT(EC5015.80 μg/mL).苦荞麸粗提物和萃取物的总酚和总黄酮含量与DPPH·和ABTS·+清除率EC50值呈负相关性.结论:乙酸乙酯萃取物具有很强的抗氧化活性,优于粗提物.据此分离苦荞麸乙醇粗提物乙酸乙酯相的抗氧化成分.     

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