天然色素甜菜红对双蛋白纤维的媒染染色

采用甜菜红色素对双蛋白纤维进行媒染染色,比较媒染剂种类对染色织物染色性能的影响,得出稀土为较适宜的染色媒染剂。探讨媒染染色温度、时间、pH值、氯化钠、甜菜红和稀土用量对双蛋白纤维媒染染色性能的影响,测试染色织物的耐洗和摩擦牢度。研究结果表明,稀土作为双蛋白纤维染色用媒染剂,其最佳染色工艺条件为:甜菜红1.5%(owf),稀土1~2 g/L,pH值2~3,媒染温度30℃左右,媒染时间约90 min,染色织物具有较深的色泽和一定的染色牢度。     

甜菜红色素的稳定性探讨

采用紫外可见光谱法对甜菜红色素的稳定性进行研究,探讨了pH、温度、时间和金属离子对甜菜红色素吸收光谱的影响,分析了甜菜红色素降解的原因。结果表明:甜菜红色素的稳定性较差,随着pH的增加、温度的升高、时间的延长,甜菜红色素的降解程度均逐渐增大。     

甜菜红色素的稳定性探讨

采用紫外可见光谱法对甜菜红色素的稳定性进行研究,探讨了pH、温度、时间和金属离子对甜菜红色素吸收光谱的影响,分析了甜菜红色素降解的原因。结果表明：甜菜红色素的稳定性较差,随着pH的增加、温度的升高、时间的延长,甜菜红色素的降解程度均逐渐增大。     

甜菜红色素对蚕丝织物染色工艺研究

对甜菜红色素染色蚕丝织物的染色性能进行了研究.研究结果表明,直接染色最佳工艺为:pH值为3,温度30℃,时间40 min;壳聚糖处理后染色和媒染染色都能显著提高上染百分率,媒染染色后摩擦牢度和水洗牢度均有所提高.     

酸性染料对大豆蛋白/牛奶/聚乙烯醇共混纤维的吸附性能

采用C.I. 酸性蓝113和C.I. 酸性蓝168对大豆蛋白/牛奶酪素蛋白/聚乙烯醇共混纤维（简称双蛋白纤维）和大豆蛋白/聚乙烯醇共混纤维（简称大豆蛋白纤维）进行染色,比较了Langmuir和Langmuir+Nerst两个染色热力学方程对实验点的模拟结果,探讨了染色温度对Langmuir+Nerst吸附常数的影响,分析了两只染料对双蛋白纤维和大豆蛋白纤维吸附性能的差异。结果表明,Langmuir+Nerst吸附模型比更适合于描述C.I. 酸性蓝113和C.I. 酸性蓝168在双蛋白纤维和大豆蛋白纤维上的吸附,染料在双蛋白纤维上的平衡吸附量高于大豆蛋白纤维,C.I. 酸性蓝113与纤维离子键结合程度高于C.I. 酸性蓝168。     

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。     

蛋白酶法胭脂虫红色素的萃取及对柞蚕丝织物的染色

利用蛋白酶与水结合的方法对胭脂虫干体内的胭脂虫红色素进行萃取,并通过天然染料胭脂虫红色素对柞蚕丝织物进行染色。利用蛋白酶进行色素提取,过程具有温度低、萃取时间短、提取效果好等特点。通过对上染工艺中的胭脂虫红色素质量浓度、染色温度、染色时间、pH值等影响因素进行单因素试验分析,得到了最佳的染色工艺为:胭脂虫红质量浓度1.5 g/L,染色温度80℃,染色时间40 min,pH值为4,浴比1∶40。     

胭脂虫红色素对羊毛织物的染色性能研究

从染液pH值、染色温度、染色时间、染料提升性等方面入手对胭脂虫红色素上染羊毛织物的性能进行研究,并对染色牢度和生态安全性进行测试.研究结果表明,胭脂虫红色素上染羊毛的最佳工艺条件为:染液pH值3～4,染色温度为80 C以上,染色时间为50～60min;胭脂虫红色素对羊毛织物具有较好的提升性;胭脂虫红色素染色的羊毛织物的金属离子含量和禁用偶氮染料含量达到生态纺织品的要求.     

双蛋白纤维的耐干热性能

在恒温条件下对大豆蛋白/牛奶酪素蛋白/聚乙烯醇共混纤维(简称双蛋白纤维)进行干热处理,探讨了干热处理温度和时间对双蛋白纤维白度、黄度、质量损失率的影响,并通过染色试验测定了干热处理条件对酸性深蓝5R染色双蛋白纤维性能的影响.研究表明,双蛋白纤维能够耐受一定的高温,随着干热处理温度的升高和时间的延长,纤维的白度逐渐下降而黄度和质量损失率逐渐增大,205℃干热处理2h或220℃干热处理0.5h后,纤维黄度和质量损失率均急剧上升,染色纤维的表观色深K/S值下降明显,220℃干热处理0.5h后再延长处理时间,纤维开始燃烧.干热处理一定温度和时间后,纤维的染色特征值有所变化,纤维的彩度C和色相角H随干热处理温度的升高和时间的延长而降低.     

牛奶蛋白纤维染色性能的研究

研究了酸性染料对牛奶蛋白纤维的染色性能,探讨了pH值、染色温度、时间、元明粉浓度等对染料上染百分率的影响,并测试分析了染色后的皂洗牢度和透染性能.得出酸性染料对牛奶蛋白纤维的最佳的染色条件:温度为90～100 ℃、染色时间为60 min左右.此外,染色pH值随染料不同而不同,羊毛专用酸性染料及弱酸性染料适宜pH值在4～5之间,强酸性染料适宜pH值在2～3之间.     

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.     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

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.