猪用生长激素(PST)脂质体制备方法和膜材的选择

本文首先对PST脂质体的制备方法进行了研究。采用薄膜法、二次乳化法、冰冻熔融法、逆相蒸发法四种方法制备PST脂质体产品，测得产品包封率分别为74．93％、76．03％、72．18％、85．03％。试验还对测定包封率的两种方法即凝胶柱分离法和鱼精蛋白凝聚法进行了比较，测得PST脂质体的包封率分别为75．26％、84．58％，PST回收率分别为90．4％和98．22％。因此确定了逆相蒸发法为本文PST脂质体的制备方法；鱼精蛋白法为试验产品包封率的测定方法。研究比较了制备PST脂质体的三种膜材。以氢化(HEPC)与非氢化(EPC)蛋黄卵磷脂制备PST脂质体的包封率分别为84．87％、86．03％。在4℃、20℃、37℃条件下贮藏HEPC—PST脂质体的渗漏率均大于EPC—PST脂质体。以大豆卵磷脂和蛋黄卵磷脂制备PST脂质体的包封率分别为71．94％、88．11％，在室温(20℃)条件下储藏，以蛋黄卵磷脂制得的PST脂质体产品稳定且颗粒均匀。结果确定非氢化蛋黄卵磷脂为本文制备PST脂质体的膜材。     

制备乳脂肪球膜磷脂-维生素A脂质体的工艺优化

目的:制备可添加于婴儿液态配方乳的乳脂肪球膜磷脂-维生素A脂质体,并优化其制备参数。方法:本实验采用薄膜水合-高压均质法,应用乳脂肪球膜磷脂为膜材,制备维生素A脂质体,在单因素实验基础之上,探讨制备脂质体过程中磷脂浓度、主药与磷脂比例、胆固醇与磷脂比例、维生素E占磷脂百分比浓度、反应温度等制备因素对形成脂质体后包封率的影响规律。采用二次旋转正交组合实验方法设计实验,经SAS软件与Matlab软件处理数据得到配方原料指标和反应温度对脂质体包封率的影响。结果:优化得到制备脂质体工艺参数:磷脂浓度7.43%,磷脂与主药比例28.95∶1,磷脂与胆固醇比例为6.53∶1,维生素E占磷脂百分比浓度为0.83%,反应温度59.58℃,得到优化后最高包封率为88.77%,脂质体在扫描电子显微镜下观察,其超微结构为球状囊泡。结论:本实验首次以乳脂肪球膜磷脂作为膜材包埋维生素A制备脂质体,将传统的薄膜水合法与高压均质法相结合,成功制备出可添加于婴儿食品的可食性脂质体。     

制备乳脂肪球膜磷脂-维生素A脂质体的工艺优化

目的:制备可添加于婴儿液态配方乳的乳脂肪球膜磷脂-维生素A脂质体,并优化其制备参数。方法:本实验采用薄膜水合-高压均质法,应用乳脂肪球膜磷脂为膜材,制备维生素A脂质体,在单因素实验基础之上,探讨制备脂质体过程中磷脂浓度、主药与磷脂比例、胆固醇与磷脂比例、维生素E占磷脂百分比浓度、反应温度等制备因素对形成脂质体后包封率的影响规律。采用二次旋转正交组合实验方法设计实验,经SAS软件与Matlab软件处理数据得到配方原料指标和反应温度对脂质体包封率的影响。结果:优化得到制备脂质体工艺参数:磷脂浓度7.43%,磷脂与主药比例28.95∶1,磷脂与胆固醇比例为6.53∶1,维生素E占磷脂百分比浓度为0.83%,反应温度59.58℃,得到优化后最高包封率为88.77%,脂质体在扫描电子显微镜下观察,其超微结构为球状囊泡。结论:本实验首次以乳脂肪球膜磷脂作为膜材包埋维生素A制备脂质体,将传统的薄膜水合法与高压均质法相结合,成功制备出可添加于婴儿食品的可食性脂质体。      

冷冻干燥对PST脂质体包封率的影响

研究了冻干保护剂的作用 ,由包封率和外观形态确定了海藻糖和蔗糖作为冻干保护剂 ,包封率达到 95 % ,外观粉针效果良好。添加比例是海藻糖∶磷脂为 1∶2 ;蔗糖∶磷脂为 2∶1。纵观整个试验以此法制备的PST脂质体显示了其具有可长期保存、防止不饱和脂肪酸氧化等优点。     

维生素E脂质体的制备工艺筛选、优化及其性质研究

目的优化维生素E（VE）脂质体的制备工艺并考察其性质。方法采用乙醇注入法、乙醚注入法、逆相蒸发法、薄膜水化法和复乳法分别制备v。脂质体,以包封率和保留率为考察指标,选择最优制备方法;经L9（3^4）正交试验设计优化选择,确定脂质体的最佳配方。结果薄膜水化法制备所得的VE脂质体包封率最高,VE保留率较高;用薄膜水化法制备脂质体的最佳配方为磷脂：VE：胆固醇=20：0．8：1．5;用透射电镜观察最佳实验组VE脂质体发现其具有指纹状结构,Zeta电位为．30．9±0．9mV,平均粒径为33．7nm。结论薄膜水化法制得的V。脂质体具有包封率高,VE保留率高,粒径均匀等特点。     

大豆磷脂阿奇霉素脂质体的制备及稳定性研究

利用大豆粉状磷脂,采用逆相蒸发结合冻融法制备阿奇霉素脂质体,以高效液相色谱法为分析手段,采用反透析法测定阿奇霉素脂质体的包封率。研究了阿奇霉素脂质体配方中不同成分的比例,以及水合介质对脂质体包封率的影响。阿奇霉素脂质体的最佳制备条件为：温度38℃,阿奇霉素：磷脂为1：20（质量比）,阿奇霉素：胆固醇为1：2．5（质量比）,最佳的水合介质是pH6．8的磷酸盐缓冲溶液,加入的磷酸盐缓冲溶液为20ml。在此条件下,阿奇霉素脂质体的包封率为72．86％。该方法准确,可用于大豆磷脂阿奇霉素脂质体的制备,并且制备的脂质体稳定。     

不同组分对PST脂质体化学稳定性的影响

通过逆相蒸发法制备PST脂质体 ,重点探讨了不同组分原料对PST脂质体化学稳定性的影响。经过实验论证 ,加入抗氧化剂后 ,包封率明显提高 ,而且加BHT的效果比加VE 的效果要好。通过对大豆卵磷脂和蛋黄卵磷脂的对比实验 ,证明了蛋黄卵磷脂所制脂质体效果较好 ,通过测定酸值 ,丙二醛含量的变化也证明了这一点     

叶绿素亚铁脂质体的制备及缓释性能研究

目的:研究制备叶绿素亚铁脂质体的方法及产品缓释性。方法:采用硫酸铵梯度法制备叶绿素亚铁脂质体,以包封率为评价指标,在单因素实验的基础上,采用正交实验确定优化工艺,考察所得脂质体的缓释性。结果:叶绿素亚铁脂质体的最佳工艺条件为:叶绿素亚铁与磷脂的比例为1∶10、胆固醇与磷脂的质量比1∶2、孵育温度40℃、硫酸铵浓度为0.2mol/L。最佳工艺条件下制得3批脂质体的平均包封率为79.5%,脂质体中芯材在PBS溶液(pH7.2)中前3h的累积释放量低于15%。结论:实验中所选参实因子对叶绿素亚铁脂质体的包封率影响显著,其影响次序为药脂比>胆固醇与磷脂的比例>孵育温度>硫酸铵浓度,脂质体具有明显的缓释效果。     

猪用生长激素(PST)脂质体生物学稳定性及促生长生物活性的研究

本文着重对PST脂质体体外稳定性进行研究 ,试验表明 :PST脂质体在猪血浆中稳定性较好。对大白鼠促生长效应实验结果表明 :PST和PST脂质体对大白鼠具有促生长活性。试验组与对照组之间差异显著 (P <0 .0 5 ) ,PST脂质体具有显著的缓释作用 ,缓释期可达 7天以上     

超临界CO_2法优化番茄红素脂质体的配方工艺

采用超临界CO_2法制备番茄红素脂质体,以包封率为指标,研究脂质体配方组成对包封率的影响。选取胆固醇与磷脂质量比、缓冲溶液pH、番茄红素与磷脂质量比为考察因素,研究各因素对脂质体包封率的影响。采用响应曲面法进行脂质体配方组成的优化,得到最佳工艺参数为:胆固醇∶卵磷脂(W∶W)为9∶20,缓冲溶液pH为7.0,番茄红素∶卵磷脂(W∶W)为1∶50,此条件下番茄红素脂质体包封率达83.4%±1.15%。该实验结果为番茄红素脂质体的制备提供了方法依据和理论基础。     

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