黄金茶中总黄酮超声提取工艺

对超声法提取黄金茶中总黄酮的工艺进行优化。利用超声法提取黄金茶中的总黄酮,考察了超声时间、超声功率、乙醇浓度、料液比4个因素对总黄酮得率的影响,通过单因素试验和正交试验确定了提取的最佳提取工艺条件。最佳提取工艺为超声时间20min,超声功率75W,乙醇浓度70%,料液比1∶20(g/mL),总黄酮得率为5.3493%。     

海金沙中多酚的超声提取工艺研究

研究了从海金沙中提取多酚的工艺条件.通过单因素实验考察了超声辅助提取过程中的乙醇浓度、超声处理时间、提取温度、料液比等因素对海金沙中多酚得率的影响.并采用正交试验进行优化.结果得出最佳提取工艺条件:以70%乙醇作为溶剂,料液比为1 ∶ 10,提取时间为60min,提取温度为70℃,海金沙中多酚得率为16.50%.     

正交试验法优选胡萝卜多糖的超声波辅助提取工艺研究

采用超声波辅助提取法浸提胡萝卜中的多糖类化合物,通过单因素试验和正交试验设计对胡萝卜多糖的提取工艺条件进行优化。结果表明,浸提温度对胡萝卜多糖的提取具有显著性影响,胡萝卜多糖超声辅助提取的最佳工艺条件为料液比1∶40(g/mL),浸提时间75 min,浸提温度70℃,超声功率420 W,在此工艺条件下胡萝卜多糖提取率高达18.43%。验证实验表明,正交试验法优化得到的提取工艺稳定可行,可作为胡萝卜多糖提取的一种有效手段。     

正交试验法优化超声提取黄米中多糖

通过单因素试验研究料液比、超声功率、提取时间、提取温度对黄米中多糖提取率的影响,再利用正交试验法优化最佳提取工艺条件,得出最佳提取工艺参数:料液比1∶23 (g/mL)、超声功率100 W、提取温度70℃、提取时间40 min,该条件下黄米中多糖的提取率为7.35%。     

表面活性剂协同超声提取陈皮中总黄酮的工艺研究

为研究表面活性剂协同超声提取陈皮总黄酮的提取工艺,采用单因素试验法考察了表面活性剂的种类及用量、乙醇浓度、料液比、超声温度等因素对总黄酮提取率的影响,结合正交试验对工艺条件进行了优化。结果表明:最佳提取工艺条件为表面活性剂选择质量分数0.5%的Tween 20、乙醇浓度60%、料液比1∶50(g/mL)、超声温度70℃,此条件下黄酮提取率可达6.83%。该法具有工艺条件简单、黄酮提取率高、成本低等优点。     

超声-微波协同萃取灰叶胡杨花粉中总黄酮的工艺研究

研究了超声- 微波协同萃取法提取灰叶胡杨花粉中总黄酮的工艺。通过单因素试验确定了影响提取总黄酮的主要因素及最佳水平范围,通过正交试验确定的最佳提取条件为：乙醇浓度70%,提取时间40min,提取次数3 次,提取温度60℃,此条件下灰叶胡杨花粉总黄酮的提取率为2.783%。     

罗平小黄姜姜酚的超声波辅助提取工艺的优化

通过单因素和正交试验研究了乙醇浓度、料液比、超声功率及超声时间对超声波辅助提取罗平小黄姜姜酚的影响。正交试验优化得到最佳工艺条件:乙醇浓度为70%,料液比为1∶15(g/mL),提取时间为15min,超声功率为120 W(80%)时,姜酚的提取率最大,为1.46%。同时抗氧化试验表明姜酚具有明显的抗氧化能力。     

超声波法提取阿魏菇多糖的工艺

研究超声波辅助提取阿魏菇多糖的方法,通过单因素和正交试验考察并确定阿魏菇多糖的最佳提取工艺。通过试验最终确定阿魏菇多糖的最佳提取工艺为:超声功率160 W、超声时间70 min、液料比30∶1(g/mL)、提取温度60℃。在该条件下,阿魏菇多糖得率为11.08%。     

雪菊中抗氧化活性物质的提取工艺研究

通过单因素实验和正交试验,考察不同因素如提取剂浓度、提取温度、提取时间、料液比等对雪菊中抗氧化成分提取效果的影响,确定最佳提取工艺条件。结果表明:在超声提取工艺下,影响提取效果的主次因素为料液比提取温度提取溶剂提取时间,最佳提取工艺条件为料液比1∶8、提取温度65℃、提取溶剂70%乙醇、提取时间3.5h。     

竹叶中活性茶多酚成分的提取研究

探讨用超声技术从竹叶中提取茶多酚的最优工艺条件。以茶多酚的产率为考察指标,在单因素试验的基础上,固定超声功率为70 W,采用L9(34)正交试验来确定浸提温度、超声时间、料液比、乙醇体积分数四个因素的最佳组合。结果表明,在超声功率为70 W的前提下,从竹叶中超声提取茶多酚的适宜工艺条件为:浸提温度75℃,超声时间40 min,料液比1∶20(g/mL),乙醇体积分数75%,此条件下茶多酚提取产率为0.624 3%。该提取工艺稳定可靠、环保,具有使用价值。     

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