离子型染料对牛奶蛋白复合纤维的染色性能

采用阳离子、中性、活性染料对牛奶蛋白复合纤维进行染色,研究温度、pH值、时间和助剂对上染百分率的影响。结果表明,牛奶蛋白复合纤维采用离子型染料染色,染料提升性,移染性好,染色牢度高。染色的最佳工艺为:阳离子染料,染色温度85℃,pH值5.0～5.5,染色时间40 min;中性染料,染色温度80℃,pH值3.5～4.5,染色时间45 min;活性染料,染色温度90℃,pH值3.5～4.5,染色时间55 min。     

阳离子染料对牛奶蛋白纤维的染色性能研究

牛奶蛋白纤维是一种在结构中含有牛奶蛋白质氨基酸大分子的线型高分子,各类染料(如酸性、中性、直接、活性、阳离子染料等)均能上染.主要研究了阳离子染料对牛奶蛋白纤维的染色性能,讨论了染浴pH值、温度、时间以及电解质(NaCl)对阳离子染料上染百分率的影响.结果表明:用阳离子染料对牛奶蛋白纤维染色日寸,染浴pH值为5～6、染色温度90℃左右、染色时间为60 min比较好;电解质起缓染作用,染色后的皂洗牢度在3级或3级以上.     

PP/共聚酯共混纤维系列染色性能研究

研究pH值、时间、温度和染浴中染料浓度等染色条件对PP/常压阳离子染料可染共聚酯共混纤维染色性能的影响。发现适宜的染浴pH值为2.8，染色温度为100℃，染色时间为2h时，染料浓度为25mg/mL，染浴中的染料浓度与纤维上的染料平衡浓度符合朗格缪尔（Langmuir）吸附等温线。同时还发现，共混纤维中基体-微纤两相结构间存在的“微隙”对显色阳离子的传导能力是有限的，该传导能力制约了纤维的染色速率。     

分散型阳离子荧光染料

采用分散型阳离子荧光染料对改性涤纶织物进行染色,研究了染料浓度、染色温度、染色时间、染浴pH值等因素对染色织物K/S值和荧光性能的影响。结果表明,分散型阳离子荧光染料上染改性涤纶织物的最佳工艺:染料2%(omf),染色温度120℃,染色时间40 min,染色pH值4.5。在该工艺条件下,改性涤纶织物具有较好的染色效果和色牢度。     

毛腈混纺针织物染色

文中介绍了毛腈混纺针织物只染腈纶、只染羊毛及毛腈一浴法染色工艺.腈纶纤维可采用阳离子染料、分散染料及分散型阳离子染料染色.羊毛纤维采用酸性染料染色.由于阳离子染料对腈纶的亲和力大,在染色过程中应加入阳离子型缓染剂,并应控制染色温度、降温速度、浴比和pH值.     

正丙醇对腈纶染色性能的影响

阳离子染料是腈纶专用染料,在实际生产中经常碰到阳离子染料匀染性差、价格较高等问题,欲增加其染深性常有困难.若在染浴中混合一些有机溶剂,可以改进纤维的结构,增加其染深性.采用正丙醇作为溶剂,通过调节染液pH值,经适当的红外线染色程序(不同种类阳离子染料染腈纶时正丙醇用量和染浴pH值是不同的),可以明显提高染色腈纶织物的表观色深,但在匀染性和水洗色牢度方面有待提高.     

阳离子改性亚麻织物对弱酸性染料的染色性能研究

报道了阳离子改性的亚麻织物对弱酸性染料的染色性能,分析了染色温度、染色时间、盐的用量、染浴pH值对弱酸性染料K/S的影响,并通过正交实验确定了阳离子改性亚麻织物对弱酸性染料的最佳染色工艺。     

阳离子染料可染聚酯织物的一浴多色染色

高温高压型阳离子染料可染聚酯纤维(CDP)、常压沸染型阳离子染料可染改性聚酯纤维(ECDP)、新型阳离子染料可染改性聚酯纤维(NECDP)3种纤维所含磺酸盐基团数量以及聚集态结构的差异,若采用阳离子染料对3种织物进行一浴染色,可得到多色效果。通过不同聚酯织物的K/S值及色差,探讨了染色pH值、温度、保温时间对多色效果的影响。结果表明:在染料质量分数为2%(omf)左右,染色温度90℃,染色时间40 min,pH值为5时,所得3种阳离子染料可染聚酯纤维织物之间的色差相对最大,一浴多色效果显著。     

醋青纤维的阳离子染料染色性能

为了解醋青纤维的染色性能,制定合理的染色工艺,分析了在不同温度以及匀染剂存在下阳离子染料上染醋青纤维的染色动力学,探讨了不同染色工艺条件下阳离子染料对醋青纤维染色性能的影响。结果表明:阳离子染料上染醋青纤维的染色动力学过程符合准二级动力学吸附模型;上染速率、平衡上染量和扩散系数均随着温度的升高而增加,半染时间随着温度的升高而减小;匀染剂的加入使上染速率、平衡上染量和扩散系数下降,半染时间增大;阳离子染料上染醋青纤维的优化工艺为:pH值4.8,温度105℃,保温时间45 min。     

羊毛/锦纶/腈纶纤维同浴染色工艺

在羊毛／锦纶／腈纶多种纤维的同浴染色中，选用弱酸性染料染羊毛和锦纶，阳离子染料染腈纶，同时在染浴中加入适量的沉淀防止剂和锦纶阻染剂，以提高染料在染浴中的稳定性。染浴的pH值一般控制在4—5，始染温度为40℃，升温至98℃保温染色，此工艺可确保三种纤维具有优异的同色性。     

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.     

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.     

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.     

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.     

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.     

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.