提高食品中益生菌数量的两大新技术

益生菌是一种对人类健康起着重要作用的微生物,并广泛应用于食品生产,然而,益生菌自身比较脆弱,容易受周围环境的影响而导致食品中益生菌菌数的快速下降,严重影响了益生菌的益生作用,因此,对益生菌进行包埋,提高食品中益生菌的稳定性和存活能力将对我们进一步开发益生菌系列产品至关重要.本文根据目前国内外益生菌包埋技术研究的现状,对目前研究较多的微胶囊包埋技术和双层包埋技术的原理,优缺点以及实际应用情况进行综述。     

基于流式细胞术的乳酸菌快速计数方法

流式细胞术是对单个细胞或其他生物微粒进行多参数、快速定量分析的先进技术。在乳及乳制品领域,该技术常用于检测发酵剂、益生菌、污染指示菌等的含量及活性。本文将以Thermo Fisher的Attune NxT平台为基础,开发建立一种基于流式细胞术的乳酸菌快速计数方法,为乳制品的快速检测提供技术参考。     

高光谱技术融合平板菌落法同步计数酸奶中益生菌

采用高光谱技术结合平板菌落法快速表征益生菌酸奶中常见的发酵菌种（保加利亚乳杆菌、嗜热链球菌）和益生菌种（干酪乳杆菌、嗜酸乳杆菌、植物乳杆菌）的光谱差异,并结合不同模式识别方法对混合菌种发酵酸奶中每种益生菌的数量进行同步计数,最后与传统计数法得到的菌落数量结果进行对比,通过2 种计数结果的差异性分析验证高光谱菌落计数的可行性。结果表明,当主成分数为9时,最小二乘支持向量机模型对不同种类菌落识别效果均优于K-最近邻法和误差反向传播神经网络模型,其中校正集识别率为99.20%,预测集识别率为93.33%,为最佳计数模型,与传统计数法并无显著差异（P＞0.05）,验证高光谱技术应用在混合菌种发酵酸奶中对每种益生菌同步计数的可行性,解决传统计数法无法同步计数混合菌种酸奶中各益生菌数量的缺陷问题,为快速无损检测酸奶品质与保健活性提供检测依据。     

益生菌包埋前沿技术及其研究进展

益生菌是对人体健康有益的一类活性微生物。由于菌体对外界环境高度敏感,在生产、储存和使用过程中容易出现存活率低或生物活性差等问题,极大地降低了益生菌的益生效果。包埋技术可以在一定程度上保护益生菌免受环境和相关因素的影响,对益生菌抵抗外界不良条件具有良好的效果。近年来,益生菌包埋技术的快速发展,为益生菌的高效保护提供了有效策略。本文综述内源乳化法、Pickering乳化法、复合凝聚法和多层包埋4种益生菌包埋前沿技术,包括其技术原理,优、缺点等方面;阐述益生菌包埋技术在食品领域的应用,包括产品在胃肠道中活菌数的变化以及对食品感官特性的影响。最后对益生菌包埋技术的研究方向与发展前景进行展望。     

益生菌功能性家纺面料的开发研究

文章以益生菌作为生态抗菌防螨整理剂,介绍了益生菌抗菌防螨机理,研究了益生菌微胶囊制备技术和负压闪爆后整理技术,开发了具有抗菌防螨性能的家纺面料,并对其进行抗菌、防螨等性能的检测。结果表明,运用该方法开发的面料物理性能优异,并且具有较好的抗菌防螨性能。     

基因芯片在益生菌筛选及功能性分析方面的应用

基因芯片技术是鉴别微生物最有效的手段之一,它不仅可以高效、快速、准确地筛选出益生菌,而且可以对其作用宿主后产生的益生功能进行分析.本文阐明了基因芯片的原理以及近年来基因芯片技术在益生菌筛选和功能性分析方面的应用.     

一种微生物检测系统在益生菌产品中应用评价

Biolumix系统提供了一种实时、简便、快速的微生物检测方法,但未在益生菌检测中得到应用.该文将Biolumix系统用于2种益生菌产品活菌数的检测,与国标方法进行比较并对应用效果作出了初步评价.结果表明,通过不同稀释度益生菌样品的仪器检测值与菌落计数值对照,线性相关关系显著,拟合度为0.96;盲样测试中平行样标准偏差≤5％,最适检测活菌范围在107～108CFU/g（mL）,检测时间≤1h.因此,在完善检测方法基础上,Biolumix检测系统能够适用于益生菌产品检验,具备准确、低稀释倍数、耗时短等优点.     

采用实时荧光定量PCR法同时定性定量检测发酵乳中多种益生菌

为快速、准确地对益生菌发酵乳中的干酪乳杆菌及罗伊氏乳杆菌进行定性、定量检测,通过设计干酪乳杆菌及罗伊氏乳杆菌种属特异性引物,建立了双重实时荧光定量聚合酶链式反应(polymerase chain reaction,PCR)检测方法。结果表明,所建标准曲线方程线性关系良好,相关系数R²均达到0.99以上。对市售产品随机抽样检测发现:样品1、样品2未添加干酪乳杆菌及罗伊氏乳杆菌。样品3中检出干酪乳杆菌(1.39±0.25)×10⁹copies/mL,未检出罗伊氏乳杆菌。自制益生菌发酵乳检出干酪乳杆菌(3.7±0.35)×10⁹copies/mL、罗伊氏乳杆菌(4.8±0.26)×10⁹copies/mL,检测结果均与所知的益生菌种类及数量信息相符。结果表明,上述建立的实时荧光定量PCR方法能够同时对益生菌发酵乳中的干酪乳杆菌及罗伊氏乳杆菌进行快速、准确地定性、定量检测,克服了平板培养法和流式细胞术的局限,具有一定的优势和应用前景。     

对酸奶中益生菌应用种类和含量的分析

从益生菌的使用状况出发,为研发新的益生菌酸奶产品提供依据。采用GNPD数据库分析国内市场上新品益生菌酸奶的益生菌添加种类,并通过选择性培养方式检测在售的几款益生菌酸奶产品中益生菌的含量。通过GNPD搜索到的61份新品益生菌酸奶中,添加嗜酸乳杆菌和双歧杆菌的分别占总量的52.5%和67.2%,且嗜酸乳杆菌和双歧杆菌组合添加的比例达到45.9%。对几款益生菌酸奶产品中益生菌含量进行检测,益生菌活菌含量在货架期内为106~108CFU/g。旨在加强对国内市场上现有益生菌酸奶产品的分析,本实验为国内首次对益生菌酸奶产品中益生菌菌种的应用状况进行分析,为益生菌酸奶的研发提供参考。     

益生菌制剂加工技术的研究概况

对目前益生菌制剂的加工技术,包括:喷雾干燥技术、冷冻干燥技术、包埋技术的研究概况进行了综述。喷雾干燥技术中优化工艺参数、热应激蛋白、细胞损伤位置和机理研究,提高益生菌制品的质量;冷冻干燥技术中保护剂、冷应激蛋白对益生菌保护作用研究;包埋技术中重点介绍了微胶囊包埋技术的包囊材料、包埋方法的研究对益生菌制剂的改良。     

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