从香蕉皮中提取多酚的研究

以香蕉皮为原料,用有机溶剂进行提取多酚.考察溶剂种类、提取温度、提取时间以及液固比对多酚提取效果的影响,通过单因素试验,得出浸提的最佳条件为:选用甲醇为溶剂、浸提温度为60℃、时间为2h、液固比为5(mL/g).     

甘薯渣中多酚类物质的提取工艺研究

本文对从甘薯渣中提取多酚类物质的工艺进行了研究.对提取溶剂的筛选表明,75%乙醇具有最佳的提取效果;用单因素试验分析了提取温度、提取时间、固液比、pH值及提取次数对提取率的影响,在此基础上对提取温度、固液比和pH值3个主要影响因素进行正交试验,确定了甘薯渣中多酚类物质的最佳提取条件为:75%的乙醇溶液,浸提液pH值为3.5,浸提次数为2次,浸提温度为80℃,浸提时间为1.5 h,固液比为1:5.     

孔雀草中脂溶性色素最佳提取条件的研究

在不同溶剂、提取时间、温度、固液比和浸提次数等条件下,通过单因素试验确定正交试验的参数,对孔雀草花瓣中脂溶性色素提取最佳工艺条件进行了研究。结果表明:其最佳的浸提条件是用乙酸乙酯作为浸提剂,在45℃下,固液比为1∶30浸提4.5h。     

均匀设计法优化橄榄叶多酚提取工艺

通过单因素试验,考察了浸提时间、乙醇浓度、固液比、物料颗粒度和温度条件对橄榄叶多酚提取得率的影响.在单因素基础上,通过均匀试验设计对橄榄叶多酚物质的提取工艺进行优化,按U8+(8^4)均匀设计表设计试验,进一步考察浸提时间、乙醇浓度、固液比和颗粒度4个因素对多酚提取得率的影响.通过DPS软件分析,得到最佳提取工艺条件:橄榄叶粉过80目筛,温度20℃,固液比1:30(g:mL),用62%乙醇水溶液为提取溶剂,提取0.8h,多酚提取得率可达8.37%.     

微波辅助提取红景天苷

以红景天粉为原料 ,以水为溶剂研究微波提取红景天苷的最佳工艺参数 ,通过单因素试验 ,分别考察了固液比、浸泡时间、微波功率、微波处理时间、搅拌时间、提取级数等因素对提取率的影响 ,探讨了微波提取的机理。得出的最佳工艺条件为 :固液比为 1∶2 0 ,浸泡时间为 1 5h ,微波功率为低 ,微波处理时间为 60s,搅拌时间为 1 5min ,提取级数为二级。在此条件下红景天苷的提取率为 90 %。     

超高压提取亚麻籽油的研究

以亚麻籽为主要原料,采用超高压的方法对其中的油脂进行提取。在单因素试验的基础上,进行多因素优化试验,得出提取亚麻籽油的最优条件。最佳提取条件为:选择浸泡溶剂为正己烷、1:8为最佳固液比、56℃为最佳提取温度、4 min为最佳保压时间、220 MPa为最佳压力值。提取率为97.42%。     

玛咖多糖提取技术研究

以玛咖干粉为原料,在单因素试验的基础上,通过L9(33)正交试验研究提取温度、提取时间、固液比对多糖提取率的影响,以确定最佳提取工艺条件.结果表明玛咖多糖最佳提取工艺条件为提取温度100℃、提取时间2 h、固液比1:40.     

超高压提取苹果多酚的工艺研究

研究在常温下超高压技术提取苹果多酚的最佳工艺,探讨了不同提取压力、保压时间、溶剂浓度和固液比等因素对提取率的影响.结果表明:超高压提取苹果多酚的最佳工艺参数是:压力200MPa,保压时间2 min,固液比1:6,提取溶剂为80%乙醇,各因素影响大小顺序为:压力＞固液比＞保压时间＞溶剂浓度;超高压条件下苹果多酚的提取率和含量均高于常压回流提取,效果分别是后者的1.2倍和1.3倍.     

潮州柑果皮中类黄酮提取工艺研究

以潮州柑果皮为原料,以乙醇为溶剂,以果皮中类黄酮提取量为考察指标,通过单因素和正交试验分析.考察乙醇浓度、提取温度、固液比以及提取时间对类黄酮提取效果的影响。最终确定乙醇浓度70%、提取温度50℃、固液比1:25、提取时间3 h 为最佳提取工艺条件。在该工艺条件下,潮州柑果皮类黄酮1次提取质量分数为14.97%。     

淡竹叶中黄酮类化合物的提取研究

为了研究淡竹叶中黄酮类化合物提取方法。本文采用超声波-醇提-酯萃法,研究了提取的各种影响因素,通过正交试验设计,寻找最佳提取条件。试验结果表明,以60%乙醇为溶剂,固液比为1:30,经20kHz超声波提取30min,再经70℃水浴回流3h为最佳,在最佳实验条件下得到2.27%的收率。在试验影响因素中,影响程度从大到小依次为溶剂>回流温度>超声时间>超声强度>回流时间>溶剂浓度>固液比。     

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