植物乳杆菌微胶囊化研究

为保护植物乳杆菌的活性以增强乳杆菌在动物肠道内的益生功能,以天然发酵玉米青贮饲料中优良植物乳杆菌作为芯材,乳清蛋白和明胶为壁材,利用喷雾干燥法制成微胶囊,并以植物乳杆菌包埋率为响应值,研究壁材配比、壁材添加量、进风温度、进料量4个因素,进行中心组合实验(Box-Behnken),通过响应面分析对喷雾干燥法制备植物乳杆菌微胶囊条件进行优化。结果表明:最优条件为壁材配比(乳清蛋白与明胶质量比)1:2、壁材添加量22%、进风温度127℃、进料量35%,在此条件下,植物乳杆菌包埋率为62.15%。结论:本研究为应用喷雾干燥法制备植物乳杆菌微胶囊奠定了基础。     

保加利亚乳杆菌微胶囊的制备及特性研究

为克服保加利亚乳杆菌不耐酸的缺点,建立制备保加利亚乳杆菌微胶囊的方法。本研究以海藻酸钠和壳聚糖复合包埋保加利亚乳杆菌,通过单因素实验和正交试验,确定了制备微胶囊的最佳工艺条件为:海藻酸钠浓度为3%、壳聚糖浓度为1.5%、氯化钙浓度为2%、120 min固化时间,微胶囊的包埋率为78.96%。该工艺条件下的保加利亚乳杆菌微胶囊具有良好的耐酸性和肠溶性。在人工胃液中,微胶囊在120 min,保持完好;而在人工肠液中,微胶囊60 min完全崩解。     

副干酪乳杆菌HD1.7微胶囊制备及质量评价

为提高益生菌副干酪乳杆菌HD1.7对环境的抗性,采用实用性强的喷雾干燥法,将菌株包埋在壁材中制成长货架期、高保护性的微胶囊制剂。通过正交试验优化了进风速度、脱脂乳粉含量、进料速度、低聚果糖含量对微胶囊细菌存活率的影响,探讨了副干酪乳杆菌HD1.7微胶囊在模拟胃肠道以及不同温度储存条件下的菌体存活率。结果表明:进风温度115℃、脱脂乳粉含量4%、进料速度6.5 mL/min、低聚果糖含量0.8%时可显著提高微胶囊化副干酪乳杆菌HD1.7的存活率,达到48.37%。副干酪乳杆菌HD1.7微胶囊在模拟人工胃液和人工肠液处理2 h分别仍有40.9%和86.77%的存活率;模拟胃液1 h转至肠液2 h后微胶囊基本崩解完全;常温封闭储存45 d时副干酪乳杆菌HD1.7微胶囊仍有94.87%的存活率,说明HD1.7微胶囊常温封闭储存时的稳定性较高。     

肠溶性植物乳杆菌微胶囊的制备及其环境耐受性和贮藏稳定性研究

植物乳杆菌ZDY2013是一株能代谢复杂碳水化合物并维持胃肠道稳态的乳酸菌,为提高菌株到达肠道的存活率,制备了肠道靶向释放植物乳杆菌的微胶囊。以植物乳杆菌ZDY2013及低聚木糖为芯材,海藻酸钠及乳清蛋白为壁材制备微胶囊;采用响应面分析法优化微胶囊的制备工艺,并对优化后的微胶囊耐受极端环境的能力及在胃肠道释放的水平进行评价;同时,考察肠溶性微胶囊的贮藏稳定性。结果表明,制备微胶囊的最佳工艺条件是海藻酸钠、乳清蛋白、氯化钙的质量分数分别为2.0%、4.0%、2.0%,微胶囊包埋率为96.67%,存活率达到95.82%;微胶囊化后,植物乳杆菌在p H值1.50和0.45%胆盐条件下孵育5 h的存活率相比对照组分别提高了25.58%和7.11%,且65℃条件下热水浴10 min后仍有67.63%的存活率;微胶囊在胃液中释放率只有0.90%,但在结肠液中释放率达81.90%,能靶向肠道释放;此外,该微胶囊在-20℃条件下贮藏60 d后,活菌数维持在1010 CFU/g以上。综上,肠溶性植物乳杆菌微胶囊具有良好的环境耐受性及肠道靶向释放特点,为植物乳杆菌ZDY2013协同低聚木糖在特定环境中的功...     

植物乳杆菌微胶囊的制备工艺优化及特性分析

益生菌发挥益生功效的前提之一是需在肠道内达到足够定植数量,部分菌株由于难以忍受胃酸、消化酶、胆汁酸等作用,限制了其益生功效的发挥。该实验利用B-390微胶囊造粒仪,以植物乳杆菌IMAU10120-1为研究对象,以海藻酸钠为壁材,通过优化海藻酸钠浓度、CaCl₂浓度、固化时间等,对其制备工艺进行优化。结果显示,植物乳杆菌IMAU10120-1微胶囊的最佳制备条件为海藻酸钠添加量1.8%(质量分数),CaCl₂添加量3.0%(质量分数),固化时间40 min。由此工艺制备的微胶囊颗粒大小均匀,粒径在300μm左右,包埋率可达到85.1%。在不加牛胆盐的人工肠液中处理60 min后活菌释放能够稳定在1.55×10¹⁰ CFU/mL,具有较好的肠溶性。微胶囊包埋技术可有效提高该植物乳杆菌对人工胃液的耐受能力。连续胃肠液中,经人工胃液处理3 h后,其存活率为85.68%;转入人工肠液继续消化8 h后,其存活率为79.36%。该研究可为乳杆菌微胶囊技术的开发提供一定的数据支持。     

内源乳化法制备干酪乳杆菌微胶囊

为提高益生菌干酪乳杆菌KLDS 1.0301对不利环境的抗性,采用内源乳化法,将菌株包埋在海藻酸钠和浓缩乳清蛋白中制成微胶囊制剂。通过响应面实验对微胶囊包埋工艺参数进行优化,并通过人工胃肠液对微胶囊的耐受性进行分析。结果表明,微胶囊的最佳制备工艺:海藻酸钠1.93%,海藻酸钠与浓缩乳清蛋白80的质量比1∶1,水油体积比1∶2.7,碳酸钙与海藻酸钠质量比1∶2.18,包埋率为93.51%。干酪乳杆菌微胶囊在模拟人工胃液中处理3 h后活菌数下降2个对数值,而未经包埋的干酪乳杆菌在相同条件下活菌数下降4个对数值。干酪乳杆菌微胶囊在人工肠液中处理60 min后,活菌数基本保持不变,表明了干酪乳杆菌微胶囊具有较好的肠溶性。将包埋的微胶囊与嗜热链球菌KLDS 3.0501和保加利亚亚种ATCC 11842在乳清粉底料中进行混合发酵,发现包埋的干酪乳杆菌在发酵期间同样能够良好产酸,并对产酸量几乎没有影响。     

传统发酵牦牛乳中2株高产胞外多糖乳酸菌在模拟消化道中耐受力的研究

从传统发酵牦牛发酵乳中分离出的2株高产胞外多糖乳酸菌,为了研究其在模拟消化道中耐受力,对2株乳酸菌(植物乳杆菌、干酪乳杆菌)分别在人工胃液、人工肠液、人工胆汁和高盐4个模拟人工胃肠道消化环境中进行培养,测其耐受力以及对Caco﹣2细胞的黏附能力。结果表明:植物乳杆菌和干酪乳杆菌在人工胃液中作用3 h的存活率随pH值的增大而增加。在pH4.5时,植物乳杆菌的存活率达到53.63%,干酪乳杆菌的存活率达到50.83%;在人工肠液中作用4h,植物乳杆菌的存活率达到了59.58%,干酪乳杆菌的存活率达到了51.42%;在胆盐环境中培养24 h后的植物乳杆菌和干酪乳杆菌活菌数随牛胆盐质量浓度的增加而降低,活菌数均保持在108cfu/m L以上;在高盐环境中培养24 h后的活菌数随盐质量浓度的增加而降低,活菌数均在108 cfu/mL以上;并且2株乳酸菌的黏附能力也很强,植物乳杆菌可以达到16.83%、干酪乳杆菌可以达到14.86%。结论:植物乳杆菌和干酪乳杆菌均能通过胃进入肠道并保持活力,而且能在肠道很好地定植,为植物乳杆菌和干酪乳杆菌作为益生菌应用在食品中提供了理论基础。     

植物乳杆菌的降胆固研究

对植物乳杆菌MA2的体外和体内降胆固醇活性进行了研究,结果显示:培养基中添加的胆固醇的初始浓度对植物乳杆菌MA2的胆固醇去除率影响显著,当胆固醇的终质量浓度为30mg/dL,不添加胆盐的条件下,菌株MA2的胆固醇去除率达到(55±4.5)%。死菌体和休眠菌体也可去除培养基中的胆固醇,且菌体细胞浓度的影响显著。添加胆盐对菌株MA2的胆固醇去除率影响显著。体外实验表明植物乳杆菌MA2通过吸附胆固醇,进而将胆固醇吸入菌体细胞中来降低培养基中的胆固醇。MA2菌株可显著降低大鼠血清总胆固醇、甘油三酯的水平,表明其作为降血脂的益生菌的应用潜力。     

复配益生元微胶囊的制备及其消化耐受性

为提高植物乳杆菌的肠胃液耐受以及释放性能,该文以植物乳杆菌和不同质量比的益生元（菊粉、黄精多糖）为芯材,海藻酸钠和壳聚糖为壁材,采用挤压法制备合生元微胶囊。通过单因素和正交试验确定微胶囊最佳制备工艺条件,并以包埋率、存活率、储存稳定性、肠胃液耐受性及释放速率为评定指标,对合生元微胶囊最佳配比进行研究。结果表明,不同质量比的益生元对植物乳杆菌均有协同生长的作用;通过正交试验得出制备微胶囊最佳工艺条件为海藻酸钠浓度2%、CaCl2浓度0.3 mol/L、壳聚糖浓度0.8%、固化时间3 h,该条件下未添加益生元的微胶囊包埋率达到80.44%,菊粉和黄精多糖的质量比为2∶3时的包埋率最高,达到92.61%,冻干后的存活率也最高,达到81.44%;通过体外模拟胃肠道发现,包埋后的合生元微胶囊对植物乳杆菌有明显的保护效果,在连续胃肠液模拟实验中,植物乳杆菌菌液数量级下降7.36 lg（cfu/mL）,而微胶囊活菌数最大降幅为1.81 lg（cfu/mL）,其中菊粉和黄精多糖质量比为2∶3时,微胶囊在胃液中的存活率和肠液中的释放率均达到最高,该质量比下的合生元微胶囊具有最优的肠胃液释放性能。     

植物乳杆菌NCU116微胶囊制备工艺的优化设计

利用乳清蛋白中的β-乳球蛋白在低pH值及胃蛋白酶存在的情况下,依然能够保持结构完整的特性,本实验以脱脂乳作为壁材的成分之一,对植物乳杆菌NCU116微胶囊的制备工艺条件进行研究。在单因素试验的基础上,应用响应面分析法优化植物乳杆菌微胶囊制备条件。以经过人工胃液处理后微胶囊中包埋的活菌数为响应值,优化后的最佳工艺条件为：海藻酸钠质量浓度2.68g/100mL,氯化钙浓度0.20mol/L,脱脂乳质量浓度4.17g/100mL。以该工艺条件制备的植物乳杆菌NCU116微胶囊粒径为1.12mm,包封率在73.49%左右。经过人工胃液处理3h后,微胶囊中的活菌数可达8.79×109CFU/g,与理论预测值(8.85×109CFU/g)较为接近。表明实验所制备的微胶囊具有较好的耐酸性。     

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