丝胶改性剂对涤纶织物抗静电整理的研究

以环氧氯丙烷、丝胶蛋白为原料,利用丝胶蛋白上的氨基在碱性条件下与环氧氯丙烷反应,制备新型丝胶改性剂,通过L9(34)正交试验得出最佳工艺条件:在N2保护下,丝胶5 g,NaOH质量分数5%,反应时间2.5 h,反应温度65℃。丝胶改性剂与碱减量后涤纶织物上的羧基发生酯化反应并固着于涤纶织物上,改善涤纶织物抗静电、吸湿性等性能。试验表明:涤纶织物表面上的电荷由原来的0.054μC变为0.001μC,抗静电效果较好;织物接触角减小,吸湿性增强。     

碱减量和等离子体处理对涤纶织物的影响

对涤纶织物分别进行碱减量和等离子体处理,采用红外光谱仪和扫描电镜分析了涤纶织物表面形态和结构,探讨了碱减量和等离子体处理对涤纶织物性能的影响。结果表明,碱减量和等离子体处理后涤纶纤维表面出现凹槽;经碱减量处理后的涤纶织物的抗静电性、透气性、吸湿性得以改善,但断裂强力大大降低;经等离子体处理的涤纶织物抗静电性、吸湿性以及透气性提高。     

丝胶蛋白对涤纶织物的亲水整理

用自制功能性单体玛巴斯A,在无氧条件下利用引发剂玛巴斯B引发自由基聚合,通过浸轧丝胶整理液,在一定温度下饱和汽蒸的方法对涤纶织物进行整理,在对涤纶织物进行接枝的同时将丝胶包覆,使丝胶整理到涤纶织物表面。采用傅里叶变换红外光谱(FTIR)、扫描电镜(SEM)和荧光分析等对整理前后织物表征分析,结果表明丝胶已在涤纶织物表面固着。对整理前后织物进行吸放湿性等相关性能的测试,表明涤纶织物经丝胶整理后回潮率、毛效和吸湿性能都得到了一定程度的改善,从而改善了涤纶织物的服用性能。     

紫外光催化法制备丝胶蛋白改性抗静电涤纶织物

涤纶纤维因缺乏亲水性基团易产生静电,文章由此提出借助丝胶蛋白改善涤纶纤维易产生静电的缺陷。研究中以甲基丙烯酸酐乙烯基化改性的丝胶蛋白和涤纶织物为原料,在紫外光辐照下进行基于自由基反应的催化接枝改性,探究了借助丝胶蛋白整理后涤纶纤维中的双键与甲基丙烯酸酐质量浓度关系及接枝改性效果。结果表明：涤纶织物经2.5 g/L十六烷基三甲基溴化铵和1 g/L氢氧化钠质量浓度预处理能促进其表面乙烯化改性,借助红外光谱和碘液着色法验证了涤纶及丝胶中引入了双键,试样强力损失较退浆织物略有降低;经紫外催化丝胶蛋白接枝后,涤纶表面氮元素含量升至2.41%,织物静电半衰期从33.47 s缩减到8.81s,表明抗静电性有明显提升。紫外光催化丝胶蛋白为涤纶织物抗静电整理提供了新方法。     

亲水性聚酯整理涤纶织物抗静电性能的研究

通过对亲水性聚酯整理后涤纶织物的抗静电性、亲水性、透气性、白度、强力和耐水洗性等性能的测试,分析了影响抗静电性能的因素,优化了亲水性聚酯对涤纶织物的抗静电整理工艺条件:整理剂质量浓度40 g/L,170℃培烘120 s,pH值控制在5左右.研究了亲水性聚酯抗静电整理对涤纶织物染色性能的影响,初步探讨了抗静电剂的作用机理.     

涤纶织物接枝丝胶蛋白改性及其服用性能研究

采用丝胶蛋白、戊二醛和壳聚糖溶液对经过碱减量处理后的涤纶织物进行接枝改性处理,并通过正交试验,探究了接枝温度、浸渍时间、丝胶浓度和戊二醛浓度对涤纶织物接枝改性的影响。结果表明:采用2%浓度的丝胶蛋白、30 min的浸渍时间、60℃的接枝温度、0.6%的戊二醛,可以使得涤纶织物吸湿性得到显著提高,回潮率从原样的0.35%提升至0.96%,织物的抗静电性也有一定的改善,静电半衰期从15 s减少至6 s。丝胶蛋白的接枝,对涤纶织物的透气性和拉伸断裂强力,不会产生大的影响,因此不会影响其穿着使用。     

丝胶对纤维素纤维的改性

主要研究丝胶对纤维素纤维表面的改性。采用ESEM（电子扫描电镜）和FTIR—ATR（傅立叶红外光谱一衰减全反射光谱）测定纤维素表面的丝胶固着；整理试样上的丝胶含量可以通过酸性染料Supranol BordeauxB染色后织物的K／S和L值计算；对整理后织物的游离甲醛含量、折皱回复性、抗张强度、抗静电性、回潮率进行了测试。ESEM和FTIR-ATR的测试结果表明，丝胶在棉织物表面固着成膜，随着整理液中丝胶的浓度增加，整理后织物上的丝胶含量也增加，染后试样色泽加深，游离甲醛含量降低；而抗张强度和折皱回复角变化则很小。同时，随着丝胶浓度的增加，试样的电阻值急剧降低，回潮率提高。     

抗静电剂LD-5的性能研究

针对涤纶纤维在穿着或生产中易产生静电问题,文中采用聚醚酯、表面活性剂与亲水硅油的复配物抗静电剂LD-5对纯涤纶针织物进行整理。采用浸轧整理方法,探讨了抗静电剂LD-5用量、p H值、焙烘温度对织物性能的影响,测试了整理后织物抗静电性能、透气性、悬垂性和弯曲性。结果表明,抗静电剂LD-5对纯涤纶针织物最佳整理工艺为:抗静电剂LD-5用量20 g/L,p H值为6,烘焙温度160℃,整理后涤纶织物的抗静电性、悬垂性有了明显的改善,且织物透气率没有明显降低。     

蚕丝蛋白对涤纶织物的亲水整理研究

将碱减量预处理过的涤纶织物放入氯化亚砜密闭气体中,以DMF为催化剂,进行酰氯化反应,得到预处理涤纶织物,然后将预处理织物放入丝胶或丝素水溶液中进行接枝反应,使得丝胶或丝素被整理到涤纶织物的表面。对整理前后织物进行红外光谱、热失重、吸放湿性、断裂强力测试分析,结果表明:采用对织物进行蚕丝蛋白整理可以有效地将丝胶和丝素整理到织物的表面上,丝胶或丝素整理后织物的亲水性和吸湿性有了明显提高,断裂强力较预处理织物没有太大变化,但是热性能有所降低。     

涤纶织物的氧化石墨烯负载及其抗静电性能

为解决涤纶织物的易起静电问题,通过多巴胺原位聚合和氧化石墨烯循环浸渍层层自组装负载实现其抗静电功能,制备一种涤纶基抗静电织物。借助扫描电子显微镜、红外光谱仪、织物静电测试仪等表征织物的结构和抗静电性能。结果表明:多巴胺的引入有利于氧化石墨烯的负载,同时增加织物表面的亲水基团,直接改善涤纶织物的抗静电性能;当氧化石墨烯质量浓度低于20 g/L时,随着其质量浓度的增加,织物的抗静电性能逐渐提高,当质量浓度保持在15 g/L时,平纹涤纶织物的表面静电压和半衰期分别为1 156 V、1.210 s,斜纹涤纶织物的表面静电压和半衰期则为1 243 V、1.510 s;经15次水洗,平纹涤纶织物的表面静电压和半衰期仍能达到1 179 V和1.290 s,斜纹涤纶织物表面静电压和半衰期可达1 263 V和1.580 s。     

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.     

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.     

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.     

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.