小米乳酸菌发酵饮料胀罐微生物的分离及鉴定

目的 对小米乳酸菌饮料胀罐微生物进行分离和菌株鉴定,并对所分离菌株的产气特性进行研究。方法 使用孟加拉红琼脂培养基、营养肉汤琼脂培养基和改良MRS琼脂培养基对小米乳酸菌饮料胀罐微生物进行分离和纯化,根据菌落形态观察、菌体形态观察、16S rRNA 序列分析并结合基质辅助激光解析/电离飞行时间质谱(ALDI-TOF MS)技术对分离菌株进行鉴定。最后将分离菌株接种到无菌小米乳酸菌饮料产品中,培养观察产气现象。结果 共分离出6株细菌,编号为B001、B002、B003、B003、B005、B006,菌种鉴定结果均为副干酪乳杆菌(Lactobacillus paracasei),6株细菌均具有产气现象。结论 副干酪乳杆菌是引起本研究产品胀罐的主要原因。     

副干酪乳杆菌ET-22及其后生元组分对白念珠菌的抑制作用

为探究具有预防龋齿功效的副干酪乳杆菌ET-22(Lactobacillus paracasei ET-22)活菌及其后生元组分(热灭活菌和分泌物)对白念珠菌的抑制作用,评价副干酪乳杆菌ET-22活菌及其后生元组分的抗氧化能力及白念珠菌菌丝转化抑制率后,采用注射免疫抑制剂和涂抹白念珠菌的方法建立ICR小鼠的口腔念珠菌病模型。造模前后,分别以饮水的方式连续给予18 d剂量为10⁹ CFU/mL的ET-22活菌以及相对应的后生元组分,研究副干酪乳杆菌ET-22对小鼠舌部组织形态及炎症因子表达情况的影响。10⁹ CFU/mL的副干酪乳杆菌ET-22对白念珠菌出芽抑制率最高,为37.84%;后生元组分中热灭活菌及分泌物抑制率分别为17.50%、28.00%。动物模型中,ET-22活菌及其后生元组分干预后,均显著降低了小鼠血清中IFN-γ含量;分泌物组显著降低了小鼠舌部组织中IFN-γ和TNF-α含量,活菌组只显著降低了TNF-α含量,活菌组和热灭活菌组显著提高了小鼠舌部组织中CCL20趋化因子含量及舌苔菌群的丰富度和多样性。组织病理切片显示：ET-22...     

副干酪乳杆菌K56调节肠道菌群及润肠通便功能研究

目的:参考保健食品检验与技术评价规范(2003版)中关于调节肠道菌群及通便功能动物实验评价方法评价副干酪乳杆菌调节肠道菌群及润肠通便功能。方法:分别以0.000867、0.00867、0.0867、0.867、8.67 mg/kg灌胃给予副干酪乳杆菌K56菌株(实验室检测菌株规格为1.5×1011 CFU/g),检测小鼠干预14 d前后双歧杆菌、乳杆菌、肠杆菌、肠球菌、产气荚膜梭菌含量,并测定干预30 d后小肠墨汁推进率、首粒黑便时间、排黑便粒数及重量,评价副干酪乳杆菌对小鼠肠道菌群及排便的影响。结果:干预14 d前后比较,各组小鼠粪便双歧杆菌、乳杆菌、产气荚膜梭菌均显著增加(P<0.05),而肠杆菌和肠球菌无显著变化(P>0.05);与对照组比较,以0.00867、0.0867、0.867 mg/kg剂量的K56干预后,小鼠肠道内双歧杆菌及乳杆菌数量显著增加(P<0.05),0.000867、0.00867、0.867 mg/kg剂量的K56干预后产气荚膜梭菌含量显著降低(P<0.05);与模型组比较,0.00867、0.867、8.67 mg/kg剂量组干预小鼠墨汁推进率显著增高(P<0.05),0.0867、0.867 mg/kg剂量组小鼠排黑便粒数与重量显著增加(P<0.05),但各剂量组对小鼠首粒黑便时间与模型对照组无显著性差异(P>0.05)。结论:副干酪乳杆菌K56菌株具有调节肠道菌群和润肠通便的作用,调节肠道菌群最佳剂量为0.0867 mg/kg(对应人体剂量1.0×108 CFU/d),润肠通便最低有效剂量为0.867 mg/kg(对应人体剂量为1.0×109 CFU/d)。     

干酪乳杆菌Zhang分类学地位及潜在益生相关基因分析

干酪乳杆菌Zhang是本研究团队筛选出的具有优良特性的益生乳酸菌菌株。传统方法难以区分干酪乳杆菌及其近缘物种。因最近乳杆菌的系统分类进行了更新，故导致Zhang的分类地位需重新确认。本研究利用比较基因组学方法分析Zhang的分类学地位、耐药基因、致病性基因和环境抗性基因特征，探究该菌株基因组上携带的细菌素基因簇和潜在益生基因。比较基因组学结果显示Zhang与副干酪乳酪杆菌模式菌株ATCC 25302T的平均核苷酸一致性值是98.49%，通过分类学数据库比对和系统发育分析确认Zhang的分类学地位为副干酪乳酪杆菌。Zhang的基因组不含有耐药基因、致病性基因和环境抗性基因。在其基因组上注释到核心肽、LanT转运和引导切割及免疫或运输功能等Carnocin细菌素基因簇。此外，Zhang的基因组编码了谷胱甘肽合成、核黄素合成、黏附因子和分泌胞外多糖等潜在益生基因。本研究更新了Zhang的分类学地位为副干酪乳酪杆菌，揭示其不含有耐药基因、致病性基因及环境抗性基因，并注释到多个潜在益生基因，为该菌株进一步开发及产业化提供了数据参考。     

类干酪乳酪杆菌PC-01的鉴定和生物学特性及其在活菌型乳酸菌饮料中的应用

目的:以菌株PC-01为研究对象,从多相鉴定、生物学特性及其发酵活菌型乳酸菌饮料的产品特性方面研究和评价该菌株。方法:通过菌株形态学、生理生化结合全基因组测序对菌株PC-01进行菌种水平的鉴定;通过菌株在不同温度、pH值下生长情况及其对不同碳、氮源利用能力方面研究其生物学特性;通过与商业化菌株LC-01对比,对PC-01制备活菌型乳饮料的能力及产品的贮藏稳定性进行评价。结果:经鉴定,菌株PC-01为类干酪乳酪杆菌(副干酪乳杆菌),该菌株pH值耐受范围3～9,生长温度范围15～50℃,最适生长温度32.5℃,对半乳糖、葡萄糖及酵母浸粉的利用能力强。菌株PC-01可在37℃下单菌株制备活菌型乳酸菌饮料,且产品在4℃和10℃下贮藏能保持较高的活菌数和良好的稳定性,与商业菌株LC-01发酵产品无显著差异。结论:菌株PC-01是一株典型的类干酪乳酪杆菌(副干酪乳杆菌),可用于活菌型乳酸菌饮料的生产,对其基本生物学特性的研究可为其工业应用奠定基础。     

鼠李糖乳杆菌Probio-M9连续传代过程中的遗传稳定性

目的：探究鼠李糖乳杆菌Probio-M9在连续传代过程中的遗传稳定性。方法：以鼠李糖乳杆菌Probio-M9为研究对象,对其传代过程中第0,25,50,75,100代的菌株形态变化、碳水化合物利用能力以及菌株代谢特性进行比较,同时应用比较基因组学分析其在连续培养100代过程中基因组水平的变化。结果：鼠李糖乳杆菌Probio-M9在连续培养100代过程中,其菌体形态、碳水化合物利用能力等表型特征及代谢特性均无显著性（P>0.05）变化,表型特征稳定。同时以鼠李糖乳杆菌Probio-M9原始菌株基因组作为参考序列,对不同代时15株菌进行测序,基因组大小及GC含量表明15株连续培养的菌株与鼠李糖乳杆菌Probio-M9原始菌株基因组均无明显差异。系统发育关系表明15株菌与原始基因组具有较近的亲缘性。从识别到的SNP位点来看,每两个代时菌株间均未发现稳定遗传的突变位点,且菌株共线性良好,从基因组水平编码基因的突变水平证实了鼠李糖乳杆菌Probio-M9在连续培养100代过程中具有稳定表型特征及代谢特性。结论：鼠李糖乳杆菌Probio-M9在连续传代过程中具有良好的遗传稳定性,为其进一步开...     

广西地区青年人肠道乳酸菌的分离及其发酵酸奶品质的评价

采用传统的可培养方法对广西青年人肠道乳酸菌进行了分离与纯化,通过16S rRNA序列分析对菌株进行了鉴定,并将筛选菌株作为酸奶发酵剂应用。结果表明,分离到的23株乳酸菌中被鉴定为发酵乳杆菌（Lactobacillus fermentum）11株,唾液乳杆菌（Lactobacillus salivarius）6株,格氏乳杆菌（Lactobacillus gasseri）2株,副干酪乳杆菌（Lactobacillus paracasei）1株,融合魏斯氏菌（Weissella confuse）2株和口乳杆菌（Lactobacillus oris）1株。筛选乳酸菌制作的酸奶之间芳香类物质差异并不显著（P＞0.05）,而酸奶样品间酸味、后味A和丰度差异较大。进一步分析表明,副干酪乳杆菌HBUAS54287、唾液乳杆菌HBUAS54223与HBUAS54248、格氏乳杆菌HBUAS54233、发酵乳杆菌HBUAS54238与HBUAS54318乳酸产生能力较强,可进一步筛选用于酸奶复合发酵剂的开发。     

黔东南地区传统发酵白酸汤中乳酸菌的益生特性及应用

本研究以发酵酸汤为试验原料,通过pH值、胆盐耐受性实验筛选性能优良的乳酸菌,经16S r RNA序列分析鉴定得菌株1-3、1-6、ST-2、ST-11,4 株为副干酪乳杆菌,ST-10和ST-12为植物乳杆菌。通过评价菌株的疏水性、黏附性、自凝聚能力,筛选出了6 株具有益生特性的乳酸菌,其中副干酪乳杆菌1-6和植物乳杆菌ST-10对二甲苯、氯仿的疏水性均大于70%,放置24 h的自凝聚率较其他菌株都较优;不同菌株对抗生素表现出的敏感性、耐药性不尽相同。结果表明：副干酪乳杆菌1-6作为发酵剂添加后对酸汤pH值、总酸度均无显著影响(P＞0.05),但是活菌数与传统老酸汤发酵效果接近。本研究筛选得到的副干酪乳杆菌1-6 是一株性能优良的益生乳酸菌,为后续酸汤发酵益生菌的开发奠定基础。     

不同来源植物乳杆菌基因组的比较分析

目的 对分离自母乳、婴儿肠道的植物乳杆菌进行全基因组测序,分析菌株间亲缘关系和细菌素合成相关基因。方法 本研究采用Illumina高通量测序平台对不同来源的植物乳杆菌进行全基因组测序,质控过滤后的数据经Unicycler组装获得基因组精细图,通过比对COG、CAZy数据库对功能基因进注释,并借助BAGEL4等生物信息学分析工具鉴别植物乳杆菌素合成相关的基因簇,分析不同来源植物乳杆菌的益生潜力。结果 本研究5株植物乳杆菌基因组平均GC含量为44 %,母乳源植物乳杆菌基因数量多于婴儿肠道源菌株。进化树和ANI分析结果显示,分离所得菌株具有较高的同源性,相同来源的菌株更倾向于聚类到一个分支。功能注释结果显示,母乳源菌株与肠道源菌株相比拥有更多编码碳水化合物代谢的基因,且拥有完整的产植物乳杆菌素基因簇。结论 植物乳杆菌基因组GC含量、功能基因数目及产细菌素基因簇结构等与分离源有一定的关联,母乳源植物乳杆菌更适于作为潜在益生菌的候选菌株,本研究为益生菌的益生潜力研究提供了遗传学基础。     

基于全基因组测序解析不同瑞士乳杆菌菌株的遗传差异——以瑞士乳杆菌H9和H10为例

目的:瑞士乳杆菌是广泛用于干酪、发酵乳饮料等领域的重要发酵剂菌种之一.以瑞士乳杆菌H9和H10为例,解析不同瑞士乳杆菌菌株间的遗传背景和基因组差异,为菌株鉴定和开发应用奠定遗传学基础.方法:以瑞士乳杆菌H9和H10为例,结合NCBI数据库中其它16株瑞士乳杆菌全基因组完成图,通过比较基因组学方法探究不同菌株之间的遗传差...     

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