改性SiOx/WPU涂膜对腐败希瓦氏菌生物被膜的抑制作用

为获得对水产品中腐败希瓦氏菌生物被膜具有优良抑制性能的水性聚氨酯(WPU)涂膜，以不同微观形貌的SiOx微纳米粒子为粗糙度构建因子，采用滴涂法制备SiOx/WPU涂膜，测定改性SiOx/WPU涂膜表面的疏水疏油性能、表面能、微观形貌和热稳定性能，揭示改性SiOx/WPU涂膜对腐败希瓦氏菌生物被膜的抑制机制。结果表明，以十六烷基三甲基溴化铵(CTAB)改性的SiOx颗粒为粗糙度构建因子制备的C-SiOx/WPU涂膜，尽管表面氟含量最高，但其水和正十六烷接触角分别为139.0°±3.5°和0°，仅表现为疏水超亲油性，热稳定性和抗细菌黏附性最差；改性气相纳米SiOx/WPU涂膜表现为超疏水超亲油性，热稳定性最好，且可以抑制腐败希瓦氏菌的初期黏附；以改进的St?觟ber法在同一溶剂体系中制备和改性SiOx微纳米粒子为粗糙度构建因子制备的改性微米级SiOx/WPU涂膜为超双疏表面，热稳定性较高，对腐败希瓦氏菌不可逆黏附的抑制最好，可有效降低生物被膜的代谢活性，减少胞外多糖(EPS)的分泌，培养24 h后其表面刚开始形成微菌落。本研究的超双疏性改性微米级SiOx/WPU涂膜可用于制备食品包装材料，为抗生物被膜材料在食品包装领域的应用提供技术支持。     

超疏水棉织物的硅水溶胶制备法

为制备超疏水纺织品,通过水性溶胶-凝胶反应,在表面活性剂作用下制备了含甲基纳米SiO2（M-SiO2）和十六烷基改性纳米SiO2（H-SiO2）水溶胶,分别采用二步法（即先用M-SiO2水溶胶对棉织物浸轧处理,再进行低表面能修饰）、一步法浸轧H-SiO2水溶胶对棉织物进行超疏水整理。结果表明,制备的M-SiO2和H-SiO2水溶胶较稳定,粒径分布较窄,而H-SiO2水溶胶更容易在棉纤维表面引入致密的低表面能粗糙疏水膜,与二步法相比,一步法整理棉织物接触角达到152.1°,滚动角为8°,沾水等级100,具有工艺简单、节省原料、动态疏水效果更佳的优势。     

超疏水纺织品的巯基-烯烃点击化学法制备及其性能北大核心

为提高聚酯纤维的疏水性能,首先使用碱化学刻蚀法在聚酯纤维表面产生活性基团羟基和羧基,同时形成粗糙结构,其次使用气相沉积法将3-巯丙基三乙氧基硅烷沉积在纤维表面形成点击点,最后通过巯基-烯烃点击化学将含氟丙烯酸酯接枝到纤维表面,对纤维进行疏水化处理,制备超疏水聚酯纤维纺织品。借助扫描电子显微镜、X射线光电子能谱仪对纤维表面形貌和表面元素进行分析,并探究了超疏水化处理后纤维表面化学稳定性及机械稳定性。结果表明,所得超疏水纺织品经2500次机械摩擦、100次家庭水洗、144 h紫外光照、72 h溶剂浸泡后依然具有良好的超疏水性。     

高速微米颗粒冲击法制备超疏水金属表面

超疏水金属表面具有自净、耐蚀、减阻、抗结冰等独特性能,应用前景广阔。为克服现有制备工艺复杂、成本较高的局限,采用简便的高速微米颗粒冲击法,冲击颗粒为直径180μm的棕刚玉,气动喷射压力0.8 MPa,冲击时间3～7 min,冲击处理后经质量浓度为6 g/L的NaOH溶液和去离子水清洗,再经氟硅烷乙醇溶液氟化处理并烘干,成功地在金属表面构建了微纳复合结构。制备的钢表面与水滴接触角160°,滚动角2.0°,铝合金表面与水滴接触角152°,滚动角2.2°,具有超疏水性。该制备方法简便,成本低,易工业化应用。     

基于溶胶-凝胶技术的毛/涤织物疏水改性研究

超疏水织物因其广阔的应用前景,深受人们的关注。文章以毛/涤织物为基材,探索不同粒径尺度溶胶整理毛/涤织物构造有效微-纳米复合结构的改性方法;并利用扫描电镜、红外光谱、热分析仪和视频接触角测量仪对改性织物的结构和性能进行表征和分析。结果表明:通过控制溶胶-凝胶工艺,可成功制备几十纳米至几百纳米不同粒径的纳米颗粒,将不同尺度纳米硅球原位结合到纤维表面,能够在纤维表面构造有效的微-纳米多级复合结构;再使用含疏水性长链的硅烷对粗糙表面进行改性,可开发具有超疏水特性的毛/涤织物。     

乳清分离蛋白纤维-多糖复合纳米颗粒负载β-胡萝卜素特性研究

以乳清分离蛋白纤维（WPN）与两种多糖菊粉（Inu）和透明质酸（HA）为原料,通过反溶剂沉淀法制备两种水溶性β-胡萝卜素纳米粒子,研究其理化性质和体外消化特性。结果表明,乳清分离蛋白纤维复合菊粉纳米颗粒（WPN/Inu/BC）和复合透明质酸纳米颗粒（WPN/HA/BC）的电位为（+48.27±0.65）mV和（+44.83±0.8）mV,包封率为（94.34±1.35）%和（99.02±0.17）%,DPPH自由基清除活性为（61.20±2.08）%和（68.85±1.84）%。WPN/Inu/BC和WPN/HA/BC复合粒子中BC半衰期为15 d和16 d。荧光光谱表明：乳清分离蛋白纤维与多糖复合后暴露出更多的疏水基团,从而与BC更好地复合。红外光谱结果显示：多糖和β-胡萝卜素一些吸收峰发生偏移,说明它们与乳清分离蛋白纤维发生相互作用。体外模拟消化试验表明：WPN/多糖/BC复合粒子具有较好的控释能力。     

负载紫檀芪的岩藻多糖-小麦醇溶蛋白纳米颗粒的制备及体外抗肝癌活性研究

紫檀芪是一种具有多种生物活性的疏水性天然产物，因低溶解度和光不稳定性而限制了其在实际中的应用。通过pH驱动法制备了具岩藻多糖涂层的小麦醇溶蛋白纳米颗粒，确定了小麦醇溶蛋白与岩藻多糖的最优质量比为8:1，以该纳米颗粒为载体包封了紫檀芪，确定了紫檀芪与小麦醇溶蛋白纳米颗粒的最优质量比为1:10，最终制得的紫檀芪-小麦醇溶蛋白-岩藻多糖纳米颗粒呈近似球形，粒径为122.34±1.08 nm，PDI为0.188±0.001，Zeta电位为-27.73±0.44 mV，包封率为94.09±1.60%，载药率为8.36±0.14%，在pH为3.0~8.0的溶液和NaCl浓度为0~20 mmol/L的溶液中具良好的稳定性，长期储存稳定性良好，光照稳定性显著强于游离的紫檀芪；红外实验表明小麦醇溶蛋白、紫檀芪、岩藻多糖三者之间主要通过静电吸引、氢键和疏水作用结合。HepG2细胞的MTT实验和凋亡实验表明，与游离紫檀芪相比，紫檀芪-小麦醇溶蛋白-岩藻多糖纳米颗粒具有显著提高的体外抗肝癌活性。     

负载辣椒素的巯基改性壳聚糖-玉米醇溶蛋白纳米颗粒制备与稳定性分析

针对辣椒素的口服局限性，采用巯基化改性制备巯基壳聚糖，与玉米醇溶蛋白复合包埋辣椒素，得到纳米颗粒递送体系。根据粒径、载药量等指标确定制备工艺，通过荧光光谱、傅里叶变换红外光谱、透射电镜等验证其包埋效果，并评价其稳定性和消化释放特性。结果显示，在巯基壳聚糖-玉米醇溶蛋白-辣椒素比例为10∶10∶1，纳米颗粒粒径为（76.05±1.06）nm，载药量为（36.85±1.22）μg/mg，通过氢键和疏水相互作用形成，形状为规则球形。此外，纳米颗粒具有较好的pH值稳定性和离子强度稳定性，在体外模拟消化过程中能够有效延缓辣椒素的释放，消化4 h后释放率仅为（40.08±4.28）%，可进一步用于辣椒素的口服递送研究。     

微乳辅助溶剂热法纳米二氧化铈的合成与表征

以十六烷基三甲基溴化铵（CTAB）/正丁醇/正辛烷/硝酸铈溶液（氨水）形成的反相微乳液体系为反应介质,并辅以溶剂热法合成纳米二氧化铈。考察了反应温度和油相与助表面活性剂的质量比对二氧化铈粉体的影响,并对制备的粉体进行X射线衍射（XRD ）以及透射电镜（T EM ）表征。通过表征可知,微乳液溶剂热法可以直接制备出纳米二氧化铈颗粒,不需进行前驱体的焙烧;随着反应温度的增加,纳米二氧化铈颗粒的粒径逐渐增大;在油相与助表面活性剂质量比增大的过程中,纳米二氧化铈颗粒的分散性更好,产物聚团减轻。     

纳米酞菁蓝15∶3的硫醇-烯点击反应法制备及性能

以正硅酸四乙酯和乙烯基三乙氧基硅烷为前驱体,通过溶胶-凝胶法先在有机颜料酞菁蓝15∶∶3表面引入双键,然后通过硫醇-烯点击反应法将巯基乙烷磺酸钠接枝在酞菁蓝15∶3表面,制备了在水相中具有自分散功能的纳米酞菁蓝15∶3粉体。结果表明,当巯基乙烷磺酸钠质量分数为40%、APS质量分数为6%时,纳米酞菁蓝15∶3粉体最小粒径为180 nm,接枝到颜料表面的巯基乙烷磺酸钠占颜料质量分数的6.17%,在不外加助剂的条件下,采用超声波处理20 min制备的分散体具有较好的耐热稳定性和离心稳定性。     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

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.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.