气调包装的调理啤酒鲈鱼片在微冻贮藏过程中的微生物群落多样性分析

为揭示调理啤酒鲈鱼片气调包装和微冻贮藏过程中的微生物变化规律及其腐败本质,为优化产品工艺和推广产品提供理论依据,采用Illumina MiSeq测序技术解析调理啤酒鲈鱼制品气调包装和－3?℃贮藏过程中微生物群落多样性,并比较其与真空包装4?℃贮藏鲈鱼片的微生物群落多样性的区别。结果表明：鲈鱼制品在贮藏过程中的优势微生物为厚壁菌门（Firmicutes）、变形菌门（Proteobacteria）、拟杆菌门（Bacteroidetes）;真空包装的未调味鲈鱼片在4?℃贮藏过程中微生物多样性比在－3?℃贮藏的气调包装调理啤酒鲈鱼丰富,且在贮藏第4天时,开始出现了索丝菌属（Brochothrix）等常见的腐败微生物,到第10天时,索丝菌属、假单胞菌属（Pseudomonas）丰度迅速增大,出现了希瓦氏菌属（Shewanella）,造成鲈鱼片彻底腐败变质;气调包装的调理啤酒鲈鱼片在第20天时才开始出现假单胞菌属和希瓦氏菌属等腐败菌,之后在CO2的抑制作用下,腐败菌丰度逐渐减小,直到货架期终点时,假单胞菌才迅速增长,且出现了嗜冷杆菌属（Psychrobacte）,造成了鲈鱼制品的彻底腐败变质。这说明气调包装联合啤酒调理的加工方式及－3 ℃贮藏可以有效延长产品的货架期。     

不同包装方式对冷鲜鸡肉微生物菌群多样性的影响

为研究不同包装方式对冷鲜鸡肉贮藏期间菌群组成的影响,本文利用Illumina MiSeq高通量测序分析了不同包装方式下的微生物多样性。结果表明,在4℃冷藏期间,MAP,VP和N₂包装能显著降低微生物数量和挥发性盐基氮含量。高通量测序表明冷鲜鸡肉贮藏初期菌种丰富度高,贮藏后期优势菌属逐渐演变为假单胞菌属、环丝菌属、不动杆菌属和希瓦氏菌属,说明它们能耐受较低的温度。与PP组相比,MAP组假单胞菌属和不动杆菌属的丰度分别降低14.8%和9.2%,而N₂组不动杆菌属和希瓦氏菌属的丰度分别降低9.6%和7.4%。VP组不动杆菌属、环丝菌属丰度下降8%和5.6%。不同包装方式对冷鲜鸡肉中的菌群影响较大,三种包装均能抑制不动杆菌属的生长,气调包装对假单胞菌属抑制效果较好,而充氮包装和真空包装对希瓦氏菌属和环丝菌属有较好的抑制效果,本研究也为未来冷鲜鸡肉所采用的包装方式提供理论基础。     

高通量测序分析不同增菌温度下冷鲜鸡肉细菌的群落多样性

采用Ion Torrent个人化操作基因组测序仪高通量测序技术,对冷鲜鸡肉贮藏过程中的细菌在4?℃与37?℃两种增菌温度下群落结构、相对丰度及演替规律进行深入研究。结果表明：在门水平上,变形菌门、厚壁菌门、拟杆菌门为3?大菌门。在属水平,4?℃条件下,贮藏前期（0～4?d）以假单胞菌属、希瓦氏菌属、不动杆菌属为主要的优势菌属,其中假单胞菌占最大的比例,最高达44.03%;在贮藏中后期（6～12?d）,类香味菌属迅速增加,含量大于假单胞菌属,成为冷鲜鸡肉贮藏中后期的优势腐败菌。在37?℃条件下,柠檬酸杆菌属、变形杆菌属、乳球菌属及未知其他菌属在贮藏前期占主要优势;到贮藏中后期,以类香味菌属、污蝇杆菌属为主,对冷鲜鸡肉腐败变质有着重要的影响。两种增菌温度下细菌群落多样性及菌群结构变化,反映了冷鲜鸡肉潜在的卫生质量风险,为后期冷鲜鸡肉冷藏过程或贮藏中温度失控情况下有效实施冷鲜鸡肉质量安全监测提供技术参考。     

盐水处理下大口黑鲈鱼片在冷藏期间的微生物变化

该实验通过平板计数法结合16S rRNA基因测序,研究了质量分数3%的盐水处理结合真空包装的大口黑鲈（Micropterus salmoides）鱼片在冷藏过程中的微生物变化。结果表明,相较于超纯水浸泡（CK）,3%盐水浸泡（SW）有效延缓了鱼片在贮藏期间的菌落总数（Total Viable Count,TVC）、肠杆菌科、乳酸菌（Lactic Acid Bacteria,LAB）、假单胞菌（Pseudomonas）和硫化氢产生菌（Hydrogen Sulfide-Producing Bacteria,HSPB）的增加。大口黑鲈鱼片在冷藏期间的优势门为变形菌门（Proteobacteria）、拟杆菌门（Bacteroides）、厚壁菌门（Firmicutes）和放线菌门（Actinobacteria）。贮藏初期的优势属主要为不动杆菌属（Acinetobacter）、鞘脂单胞菌属（Phingomonas）、伊丽莎白菌属（Elizabethkingia）和金黄杆菌属（Chryseobacterium）,而贮藏末期为不动杆菌属。盐水处理降低了贮藏初期中不动杆菌属、伊丽莎白菌属、栖水菌属（Enhydrobacter）、巨型球菌属（Macrococcus）和沃氏黄杆菌属（Wautersiella）等优势菌群的相对丰度。采用盐水处理可以有效延缓大口黑鲈鱼片在贮藏初期的微生物生长,为大口黑鲈的保鲜应用提供参考。     

60Coγ-射线及电子束辐照对冷鲜鸡菌群多样性的影响

为探明γ-射线与电子束辐照对冷鲜鸡微生物含量和微生物群落多样性的影响,采用2.5 kGy剂量的γ-射线和电子束辐照处理真空包装冷鲜鸡,对其贮藏期内菌落总数、群落结构进行测定分析。结果表明,两种射线均能显著(P<0.05)降低冷鲜鸡菌落总数;高通量测序后得到了9门,62属的菌群结构,在门水平上,变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)、梭杆菌门(Fusobacteria)、拟杆菌门(Bacteroidetes)为优势菌群;在属水平上,贮藏0 d时,对照组内环丝菌属(Brochothrix)、希瓦氏菌属(Shewanella)、不动细菌属(Acinetobacter)为优势菌群;贮藏5 d时,对照组内希瓦氏菌属(Shewanella)、γ-射线组内嗜冷菌属(Psychrobacter)、电子束处理组内希瓦氏菌属(Shewanella)为优势菌群;贮藏10 d时,对照组内嗜冷菌属(Psychrobacter)、γ-射线组不动细菌属(Acinetobacter)、电子束处理组内希瓦氏菌属(Shewanella)为优势菌群;贮藏15 d时,对照组内嗜冷菌属(Psychrobacter)、γ-射线组希瓦氏菌属(Shewanella)、电子束处理组内希瓦氏菌属(Shewanella)成为优势菌群。由此可知,γ-射线与电子束辐照均对冷鲜鸡微生物数量和群落结构产生显著(P<0.05)影响。     

基于高通量测序分析不同保鲜冰处理对鲈鱼菌群组成与代谢功能的影响

目的：分析不同保鲜冰处理下鲈鱼微生物菌群变化及其与品质指标的相关性。方法：分别采用流化冰（slurry ice,SI）、酸性电解水冰（acidic electrolyzed water ice,AEWI）和碎冰（crushed ice,CI）对鲈鱼进行处理,测定鲈鱼的总挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量与K值,并利用高通量测序技术对样品菌群结构和代谢功能进行比较分析。结果：SI和AEWI对鲈鱼均有一定的保鲜作用,其中SI抑制鲈鱼蛋白质和核苷酸降解速度的效果最显著。在冰藏前期（0～3 d）,AEWI与CI组样品中芽孢杆菌属（Bacillus）、乳球菌属（Lactococcus）、大洋芽孢杆菌属（Oceanobacillus）相对丰度明显高于SI组。冰藏中、后期（12～21 d）,SI组样品中假单胞菌属（Pseudomonas）、希瓦氏菌属（Shewanella）、摩替亚氏菌属（Moritella）、埃希氏杆菌属（Escherichia）和别弧菌属（Aliivibrio）相对丰度明显增加,AEWI组样品假单胞菌属（Pseudomonas）和不动杆菌属（Acinetobacter）相对丰度所占比例逐渐增大,CI组中不动杆菌属在21 d时达27.77%,成为造成鲈鱼贮藏中、后期腐败的主要菌属。主成分分析表明,冰藏方式及贮藏时间对鲈鱼菌群结构组成有较大影响。鲈鱼菌群中与TVB-N含量、K值呈正相关的有假单胞菌属、不动杆菌属、嗜冷杆菌属（Psychrobacter）和希瓦氏菌属,它们可能是鲈鱼冰藏期间的优势菌。CI和AEWI组鲈鱼细菌中参与氨基酸、脂质和碳水化合物代谢的相关基因相对丰度高于同一时期的SI组,这在一定程度上从细菌代谢水平解释了SI能延缓鲈鱼腐败的原因,为后期进一步从微生物抑制机制上优化鲈鱼贮藏保鲜技术提供了理论参考。     

生鲜罗非鱼片在冷藏过程中细菌群落演替的PCR-DGGE分析

分析了生鲜罗非鱼片在腐败过程中细菌群落的演替规律。以4℃有氧冷藏条件下的生鲜罗非鱼片为研究对象,定期提取鱼片上的细菌总DNA,采用16S rDNA PCR-DGGE技术连续分析细菌群落演替,对DGGE电泳胶片上的主要DNA条带进行序列分析并构建系统发生树。结果表明:9个主要的DNA条带所代表的细菌来源于以下几个属:希瓦氏菌属(Shewanella)、无色杆菌属(Achromobacter)、不动杆菌属(Acinetobacter)、嗜冷杆菌属(Psychrobacter)、假单胞菌属(Pseudomonas)、短杆菌属(Brevibacterium)、迪茨氏菌属(Dietzia)、紫色杆菌属(Janthinobacterium)、黄杆菌属(Flavobacterium)。在冷藏初期即第0～6d鱼片上的细菌包括8个属,即无色杆菌属、希瓦氏菌属、嗜冷杆菌属、假单胞菌属、不动杆菌属、短杆菌属、迪茨氏菌属、紫色杆菌属;冷藏9d后鱼片发生腐败,此时无色杆菌属、希瓦氏菌属、嗜冷杆菌属和假单胞菌属的细菌成为优势种;冷藏12d时出现黄杆菌属细菌。     

采样方法对冷鲜鸡表面细菌DNA提取及高通量测序结果的影响

目的:比较涂抹法和冲洗法对冷鲜鸡表面细菌DNA提取及高通量测序结果的影响。方法:将4只冷鲜鸡对半分开,分别采用涂抹法和冲洗法采集其表面微生物,提取基因组DNA,对细菌16S rRNA基因V3~V4区进行聚合酶链式反应扩增,通过Illumina Hiseq测序平台对扩增产物进行高通量测序,使用QIIME等软件对测序序列进行分析统计。结果:两种方法采集的样品在细菌基因组DNA提取、菌群丰富度、多样性及菌群结构等方面均无显著差异(P0.05)。高通量测序结果表明,冷鲜鸡表面细菌菌群主要分布于7个门,10个属。变形菌门为优势菌门,占70%以上;希瓦氏菌属、假单胞菌属、不动杆菌属、嗜冷杆菌属和环丝菌属为优势菌属,分别占10%~20%。结论:两种采样方法对冷鲜鸡表面细菌DNA提取及高通量测序没有明显影响,但冲洗法比涂抹法简单易行,且不易发生二次污染,因此更具有实用性。本实验同时也为冷鲜鸡表面细菌的研究提供了数据资料。     

冷鲜猪肉贮藏过程中细菌群落结构演替规律分析

为探究冷鲜猪肉在贮藏过程中细菌群落结构的演替规律。将新鲜猪肉使用非密封包装进行低温贮藏,每天取样1次(共10 d),测定每日样品的pH值和挥发性盐基氮含量,并通过16S r DNA高通量测序技术分析细菌的多样性、群落组成和演替规律,探究细菌群落变化与腐败指标之间的相关性。通过Alpha多样性分析可知,猪肉在冷藏过程中细菌丰度和多样性总体上呈"三级台阶"的下降,丰度和多样性最高点在D3。在门水平上优势菌为变形菌门、厚壁菌门和拟杆菌门;在目水平上优势菌为假单胞菌目和肠杆菌目;在属水平上优势菌为假单胞菌属、不动杆菌属和泛菌属。对各菌属相对丰度变化的分析表明假单胞菌属,与肠杆菌属、泛菌属之间存在互生关系。细菌相对丰度和腐败指标的相关性表明猪肉腐败过程中拉乌尔菌属和醋杆菌属的相对丰度与挥发性盐基氮含量具有较强的相关性。     

暗纹东方鲀冷藏期间细菌群落结构与功能变化

目的：探究暗纹东方鲀（Takifugu obscurus）冷藏期间的微生物群落结构与功能变化规律，明确贮藏过程的优势菌属。方法：通过高通量测序技术研究冷藏期间（4℃，8 d）暗纹东方鲀细菌群落结构组成与变化规律，利用Tax4Fun2软件进行细菌群落功能预测，并测定其挥发性盐基氮（Total Volatile Basic-N,TVB-N）、pH、感官评分等指标变化。结果：高通量测序表明贮藏期间样品细菌群落发生显著变化，初期的主要菌属有不动杆菌属（Acinetobacter）、乳杆菌属（Lactobacillus）、气单胞菌属（Aeromonas）、假单胞菌属（Pseudomonas）等，贮藏后期假单胞菌属（Pseudomonas）的相对丰度增至91.7%以上，成为优势菌属。贮藏初期α多样性指数较高，贮藏后期明显降低。细菌群落功能预测结果显示贮藏后期的氨基酸代谢、细胞交流、膜运输等功能通路丰度升高。贮藏后期样品pH、挥发性盐基氮值、菌落总数呈上升趋势，感官评分呈下降趋势。结论：样品贮藏过程中，微生物群落结构与功能发生明显演替，假单胞菌属（Pseudomonas）是贮藏过程中的优势菌属；该结...     

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