正交试验法优化草莓中总黄酮的提取工艺研究

对草莓中黄酮类物质的提取工艺进行了优化,在单因素的基础上,采用L9(34)正交试验设计,研究乙醇浓度、料液比、提取时间和提取温度对草莓总黄酮得率的影响.结果表明,水浴回流提取草莓总黄酮的影响因素顺序依次为乙醇浓度＞料液比＞提取时间＞提取温度,草莓总黄酮的最佳提取工艺条件为固液比1∶35 (g/mL)、乙醇浓度55％、提取时间130min、提取温度60℃,此条件下总黄酮得率为5.13mg/g.     

啤酒花总黄酮超声波提取工艺的研究

研究啤酒花总黄酮的最佳提取工艺。利用单因素试验研究了超声波提取法、水浴回流提取法、提取溶剂的种类和浓度、料液比、提取温度和时间对啤酒花总黄酮提取量的影响,并通过正交试验确定了啤酒花总黄酮的最佳提取条件。结果表明,啤酒花总黄酮最佳提取条件为：乙醇体积浓度为40%,料液比1g∶40mL,提取温度60℃,超声波提取时间40min。在此提取条件下,啤酒花总黄酮提取量为63.55mg/g。     

蓝果忍冬总黄酮提取工艺研究

采用乙醇提取法提取蓝果忍冬中总黄酮,并采用分光光度法,以芦丁为标准品测定蓝果忍冬果实中总黄酮的含量.通过单因素实验分析了乙醇浓度、料液比、提取温度及提取时间四个主要因素对提取液中总黄酮含量的影响.再在单因素实验的基础上通过正交实验设计优化蓝果忍冬果实总黄酮的提取条件.结果表明:蓝果忍冬果实总黄酮的最佳提取条件为乙醇浓度70%,料液比1:50,提取温度50℃,提取时间2.5h.此条件下总黄酮的含量为27.44mg/g.     

余甘子叶总黄酮的超声波法提取工艺优化及其抗氧化能力研究

以余甘子叶为原料,采用超声法提取总黄酮物质,并进行抗氧化能力测定。结果表明,余甘子叶总黄酮的最佳提取工艺为料液比1:25(g/mL)、乙醇浓度60%、超声功率70 W、提取时间20min、提取温度60℃,此条件下的余甘子叶总黄酮提取率高达14.57%。余甘子叶总黄酮具有较强的自由基清除能力,当浓度为0.5mg/mL时,·OH清除率为82.72%,NaNO_2清除率为66.14%;当浓度为0.08mg/mL时,DPPH·清除率为97.40%。     

余甘子中水解性单宁的提取及其功效研究

采用水浴法提取余甘子中低分子水解单宁,比较了乙醇浓度、料液比、提取温度、提取时间对单宁提取率的影响,并通过正交试验对余甘子中单宁的提取工艺进行了优化,同时对提取物的抗氧化性做了研究。结果表明,提取余甘子水解单宁的最优工艺参数为:乙醇浓度60%、料液比1:30、提取温度85℃、提取时间1.5h,此条件下余甘子单宁的提取率为8.84%。余甘子中低分子水解单宁具有较强的抗氧化活性,是一种极具潜力的抗氧化剂。     

粗子草总黄酮的提取工艺研究

粗子草是一种稀有的伞形科药用植物,当地人泡茶饮用可用做抗炎及降血压用。以乙醇为提取剂,设计单因素实验和正交试验,考察了乙醇浓度、料液比、提取时间、提取温度对粗子草中总黄酮得率的影响。结果表明:粗子草富含黄酮;各因素对粗子草总黄酮提取的影响顺序是:提取温度乙醇浓度料液比提取时间;粗子草总黄酮最佳提取工艺为:乙醇浓度60%,料液比1∶30(g/m L),提取时间90 min,提取温度60℃。研究可为药用植物粗子草的保护性开发提供参考。     

石仙桃中总黄酮的提取方法的比较研究

探究石仙桃的总黄酮的提取方法的比较。以乙醇-水为提取体系,分别采用回流法、超声法,探究乙醇浓度、料液比、提取时间等对石仙桃中总黄酮提取的影响,确立最佳条件。通过正交试验证明,超声波辅助提取的最佳工艺为:温度40℃,料液比1∶40(g/mL),提取时间50 min,在此条件下提取的黄酮含量为26.12 mg/g;乙醇回流法提取最佳工艺为:温度60℃,料液比1∶50(g/mL),提取时间50 min,在此条件下提取的黄酮含量为22.03 mg/g。超声波辅助提取法提取石仙桃中总黄酮的提取率高于乙醇回流提取法提取。     

正交实验法优化紫花苜蓿总黄酮的提取工艺

本文采用正交试验法研究了紫花苜蓿MF-9中总黄酮提取的4个主要影响因素(超声时间、超声温度、乙醇浓度和料液比).结果表明:超声温度是影响紫花苜蓿总黄酮含量的主要因素,在乙醇浓度60％,超声温度55℃,料液比1∶40,超声时间为1h的条件下提取总黄酮含量为10.0057mg/g.该工艺简便省时,重现性好,是提取紫花苜蓿总黄酮的有效途径.     

诺丽(NONI)果与叶中总黄酮的提取工艺

利用L9 (34) 正交试验法研究了Noni果与叶中总黄酮的提取工艺条件及其含量测定.结果表明:对Noni果中总黄酮的提取效果影响最大的因素是提取时间,其次是乙醇浓度和提取温度,影响最小的是料液比.总黄酮的最佳提取工艺条件为提取温度为75℃,提取时间为4.0h,提取溶剂为75%的乙醇,料液比为1 ∶ 30,Noni果粗提物中总黄酮的含量为22.91mg/g.对Noni果叶中总黄酮的提取效果影响最大的因素是提取温度,其次是料液比和乙醇浓度,影响最小的是提取时间.总黄酮的最佳提取工艺条件为提取温度为85℃,提取时间为4.0h,提取溶剂为80%的乙醇,料液比为1 ∶ 35,其总黄酮的得率为33.04mg/g.     

五味子叶中总黄酮最佳提取工艺研究

用单因素试验和正交试验考察了料液比、提取时间、提取温度及乙醇浓度对五味子叶总黄酮含量的影响。结果表明:料液比为1:35,75%乙醇在85℃超声提取60min,为最佳条件;此条件下,7月份和8月份五味子叶的总黄酮平均含量分别为6．0285mg/g和8．0714mg/g。     

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