坛紫菜蛋白质提取工艺优化及其特性分析

为了开展坛紫菜高值化加工利用，以坛紫菜为原料、蛋白质提取率为评价指标，通过考察提取溶剂、超声时间和功率、料液比、pH等单因素实验、正交试验设计优化超声波提取工艺，对其等电点、乳化性、起泡性等基础特性进行分析，并进行抗氧化活性测定。结果表明，在超声全程时间50 min、超声功率1350 W条件下，坛紫菜蛋白质提取率为60.98%±1.01%。同时通过对所提取的坛紫菜蛋白质特性分析结果显示，坛紫菜蛋白质的等电点为4.5，在等电点附近，坛紫菜蛋白质有较好的泡沫稳定性，可达80.84%±2.95%；抗氧化测定结果显示，坛紫菜蛋白质在5~50 mg/mL范围内具有较强的抗氧化活性，浓度为50 mg/mL时，总抗氧化能力为2.89±0.09 U/mL，ABTS+自由基清除能力相当于0.83±0.08 mmol/L Trolox，DPPH清除率在10 mg/mL时达到68.04%±0.73%。该研究可以为坛紫菜资源的开发利用提供一定的理论依据和技术支持。     

超声辅助提取盐碱地苦菜多酚及其抗氧化活性研究

以总多酚提取率为指标,采用单因素及正交试验优化苦菜多酚的提取工艺条件;以自由基清除率为指标,用抗坏血酸作对照品,研究苦菜多酚的抗氧化活性。结果表明,最佳提取工艺条件为超声功率为150 W、乙醇浓度60%、超声温度55℃、超声时间40 min、料液比1∶50 (g/mL)、提取3次。在该工艺条件下,苦菜多酚的提取率为65.3 mg/g。苦菜多酚对DPPH·清除作用的IC50值为1.44μg/mL,对·OH清除作用的IC50值为83.72μg/mL,其清除能力均强于抗坏血酸,表明盐碱地苦菜多酚有较好的抗氧化活性。     

响应面试验优化超声辅助提取金银花叶黄酮工艺及其抗氧化活性

为提高金银花叶中黄酮类化合物的提取率,在乙醇体积分数、提取温度、液料比和超声功率4 个单因素试验的基础上,通过二次通用旋转组合设计试验优化金银花叶黄酮的超声辅助提取工艺条件,并对其体外抗氧化活性进行研究。结果表明,在乙醇体积分数60%、液料比65∶1（mL/g）、提取温度46 ℃、超声功率250 W的条件下金银花叶黄酮提取率最高,可达15.67%,与模型预测值相符。抗氧化实验结果表明,金银花叶黄酮具有较强的抗氧化能力,其清除超氧阴离子自由基的能力与作用时间呈反比,与提取液质量浓度呈正比;清除羟自由基的IC50值为0.11 mg/mL,是对照品的34 倍。     

皂荚多糖提取工艺及其抗氧化活性的初步研究

以皂荚多糖提取率为指标,通过单因素实验和正交实验探索皂荚多糖提取过程中料液比、提取温度、提取时间及提取次数对皂荚多糖提取率的影响,结果表明皂荚多糖的最佳提取条件为：料液比1：45,50℃回流提取70min,提取两次,多糖提取率为35.46%。抗氧化活性的实验结果表明,皂荚多糖有较强的羟自由基（·OH）清除作用,其IC50为0.6379mg/mL,但抑制超氧阴离子自由基（O2-·）的能力较弱,其IC50为7.5758mg/mL。     

响应面法优化水龙多酚提取工艺及其抗氧化活性研究

摘要:目的 优化水龙多酚的提取工艺,测定其抗氧化活性。方法 以水龙多酚提取量为检测指标, 在单因素实验基础上运用Box-Behnken响应面法设计四因素三水平提取实验;对优选的提取方法得到的水龙多酚进行抗氧化活性测定。结果 最佳工艺条件为：超声时间40min、超声功率550w、乙醇浓度40%、料液比1:26（g/mL）,在此条件下水龙多酚的提取率为28.55±0.21mg/g,其DPPH自由基清除IC50为39.1μg/mL,ABTS自由基清除IC50为108.1μg/mL。结论 提取工艺优化后,水龙多酚提取率增加,得到的水龙多酚具有较好的抗氧化活性。     

木豆叶球松素的超声提取工艺及其抗氧化活性研究

在考察单因素(甲醇浓度、提取时间、提取温度和料液比)实验条件对木豆叶中球松素提取率影响的基础上,采用正交实验设计法优化得到球松素的最佳提取工艺条件,同时通过DPPH自由基清除实验评价了提取物的抗氧化活性.结果表明,木豆叶中球松素超声提取的最佳工艺条件为,甲醇提取浓度80％,提取时间60min,提取温度50℃,料液比1∶40(g/mL),球松素的提取率可达到1.832mg/g;甲醇提取物清除自由基的IC50值为0.281 mg/mL.本研究建立的木豆叶中球松素的超声提取工艺具有提取效率高、操作简便等优点,适合木豆叶中球松素的提取,且甲醇提取物具有良好的抗氧化活性.     

费约果叶片总黄酮提取工艺优化及其抗氧化活性研究

对费约果叶片总黄酮的提取工艺和抗氧化活性进行了研究。结果表明:费约果叶片总黄酮最佳提取工艺为温度50℃、料液比1∶30(g∶mL)、提取时间50 min和甲醇体积分数70%。根据最佳提取工艺,重复3次得到总黄酮量分别46.89、44.51、48.27 mg/g,具有稳定性和可操作性;另外,通过半抑制浓度IC50衡量费约果叶片总黄酮提取物抗氧化活性,其抗脂质过氧化能力(IC500.275 mg/mL)和DPPH.自由基的清除能力(IC500.798 mg/mL)均优于抗坏血酸(IC500.643、IC500.917 mg/mL),而超氧阴离子自由基的清除能力(IC500.774 mg/mL)和羟自由基的清除能力(IC500.278 mg/mL)均弱于抗坏血酸(IC500.537I、C500.275 mg/mL)。     

响应面法优化超声辅助提取覆盆子水溶性蛋白工艺及抗氧化研究

以覆盆子原料,采用响应面法优化超声辅助提取覆盆子水溶性蛋白工艺,并研究其体外抗氧化活性。在单因素试验的基础上,以超声时间、料液比、pH为影响因素,以覆盆子水溶性蛋白含量为响应值,优化提取工艺条件,并通过DPPH自由基和ABTS自由基清除能力对其抗氧化能力进行评价。结果表明,覆盆子水溶性蛋白的最佳工艺条件为超声功率为250W、超声时间为22.3min、料液比为1∶20、pH为10.3,在此条件下,水溶性蛋白的含量为6.27mg/g。覆盆子水溶性蛋白对DPPH、ABTS均有较好的清除能力,其IC50值分别为0.52mg/mL、1.04mg/mL。     

鹿茸菇多酚提取工艺优化及其抗氧化活性

该文选取液料比、提取温度、提取时间、超声功率4个因素,以多酚得率为指标,应用响应面设计对超声辅助水提鹿茸菇多酚工艺进行优化,同时对鹿茸菇多酚体外抗氧化活性进行探究。响应面设计结果显示鹿茸菇多酚最优提取工艺为液料比 76∶1（mL/g）,超声功率 250 W,提取温度 60 ℃,提取时间 90 min,多酚得率为（16.591±0.173）mg/g。体外抗氧化活性测试结果显示鹿茸菇多酚总抗氧化能力EC50=0.123 mg/mL,对DPPH和ABTS+自由基均表现出较强的清除活性,IC50分别为0.303 mg/mL和0.008 3 mg/mL。该研究表明鹿茸菇多酚提取工艺可行,鹿茸菇多酚具有较强的抗氧化能力。     

响应面优化罗汉松总黄酮提取工艺及其抗氧化性研究

研究了罗汉松总黄酮提取工艺及其抗氧化活性。在单因素试验基础上,采用响应面法对乙醇浓度、液料比、超声功率、提取时间4个因素进行优化,得到罗汉松总黄酮的最佳提取工艺:乙醇浓度73.5%、液料比49∶1(mL/g)、超声功率500 W、提取时间40min,在该条件下罗汉松总黄酮的提取率达到6.271%。体外抗氧化性研究表明,罗汉松总黄酮对DPPH自由基、羟自由基、超氧阴离子的IC50分别为0.369、0.487、0.520 mg/mL,其对3种自由基的清除能力虽然弱于维生素C,但仍表现出较好的抗氧化活性。     

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