羊毛针织物蛋白酶防毡缩整理的研究

文章对碱性蛋白酶在羊毛针织物的防毡缩整理上的应用进行了研究.通过正交试验得到最佳工艺条件为:双氧水体积分数40 mL/L、温度45℃、时间45 min、pH值8,蛋白酶3%(owf)、温度45℃、时间35 min、pH值8.经此工艺条件处理的羊毛针织物,防毡缩性和悬垂性都有提高.     

中性蛋白酶对羊毛的防毡缩整理

应用枯草杆菌中性蛋白酶对羊毛织物进行防毡缩整理,通过单因素平行实验研究了蛋白酶浓度、温度、时间以及pH值对防毡缩整理效果的影响,确定了各影响因素的最佳水平.采用优化后的工艺参数,即酶浓度5%(owf),温度40℃,处理时间35 min,pH值7.5,处理羊毛织物,可以使羊毛织物的相对面积毡缩率由未整理布样的9.31%下降到1.99%,达到了机可洗水平.处理后织物的手感、光泽和白度都有了很大的改善.     

羊毛纱线KMnO_4防毡缩整理

采用KMnO4氧化法对羊毛纱线进行防毡缩处理,通过分析KMnO4用量和处理温度、pH值及处理时间对羊毛纱线力学性能、定向摩擦效应的影响,优选出最佳工艺。为了直观检验最佳工艺的防毡缩效果,采用此工艺处理羊毛机织物并测试其缩水率,结果表明:经KMnO4处理织物达到国际羊毛局TM31机可洗防毡缩标准。羊毛纤维Allwrden反应光学图片观察和扫描电镜分析表明,KMnO4剥蚀了羊毛纤维表面鳞片层,鳞片边缘变得模糊平坦。同时,这种方法还能够避免传统的氯化法所造成的环境污染。     

超临界CO2在羊毛防毡缩整理中的应用

文章研究了利用超临界CO2流体对羊毛纤维进行预处理,再采用蛋白酶对羊毛纤维进行剥除鳞片处理,使羊毛纤维具有防毡缩性能.结果表明:经超临界CO2流体处理后,纤维的润湿性能明显提高;在相同的蛋白酶处理条件下,经超临界CO2流体预处理的羊毛纤维防毡缩性能提高,断裂强力下降较小.超临界CO2的最佳预处理条件为:压力15 MPa,温度80℃,时间30 min.     

脂肪酶-过氧乙酸对羔羊毛的改性处理

介绍了使用脂肪酶、过氧乙酸、过氧化氢酶对羔羊毛进行改性处理,并对实验结果进行了正交分析,得出了羔羊毛脂肪酶-过氧乙酸改性处理的最佳工艺:过氧乙酸质量浓度为4 g/L;处理溶液pH值5,温度35℃,时间35 min.研究表明,过氧乙酸质量浓度、处理液pH值、处理时间和温度对羔羊毛的拉伸强度和摩擦性能有不同程度的影响,特别是温度、过氧乙酸质量浓度2个因素对羔羊毛拉伸强度、摩擦性能影响较大.     

纯毛绒线蛋白酶防毡缩整理的研究

采用S16.0蛋白酶处理纯毛针织绒线,可降低羊毛毡缩性,提高羊毛衫的尺寸稳定性.在浴比1:25,pH值8～10,温度45～55℃的处理液中,酶处理最佳工艺为,S16.0蛋白酶用量0.25%～0.5%(owf),平平加00.1%～0.5%,保持时间60min,其防毡缩绒线的减量率达到了5.22%.蛋白酶防毡缩属于绿色加工技术,处理后的羊毛手感柔软,不易泛黄.     

低温等离子体和蛋白酶联合处理对羊毛织物性能的影响

文章采用低温等离子体和蛋白酶联合处理技术对羊毛表面进行改性,探讨了等离子体和蛋白酶处理对羊毛抗毡缩性、润湿性能的影响。结果表面:等离子体处理羊毛最佳工艺为:时间3 min、压强50 Pa、功率150 W,蛋白酶处理羊毛最佳工艺为:蛋白酶用量2%(owf)、时间40 min、温度50℃、pH值8,低温等离子体和蛋白酶联合处理使羊毛织物抗毡缩性能提高,能够有效去除羊毛表面鳞片。     

超声波协同蛋白酶对毛织物的防缩工艺研究

在超声波条件下采用蛋白酶Maxacal L处理羊毛织物,通过对酶用量、温度、频率、pH值等进行单因素试验,得出,pH值对毡缩率影响最大。采用正交试验得出羊毛防缩最佳处理工艺:酶用量5%(owf),pH值9,温度45~55℃,频率35 k Hz;并在同一条件下将氧化前处理、酶处理、酶/超声波3种工艺数据比较,结果表明:3种工艺中,利用超声波条件协同酶处理后的羊毛织物,防毡缩性能最佳,手感保持较好,白度增加,但强度并没有明显降低。     

毛织物蛋白酶处理工艺的灰色关联分析

运用灰色关联分析方法讨论了蛋白酶处理时的工艺参数对毛织物毡缩率和失重率的影响。结果表明,影响毛织物毡缩率的因素从大到小依次为pH值、温度、处理时间和酶浓度;影响羊毛失重率的因素从大到小依次为处理时间、pH值、温度和酶浓度。     

羊毛生物酶联合防毡缩整理

针对传统的氯化法羊毛防毡缩技术对环境污染严重,单一蛋白酶防毡缩整理技术效果不理想,一浴两步酶处理法工艺流程长、强力损伤大等问题,采用蛋白酶与生物酶活化剂联合组成的混合溶液协同对羊毛进行一浴一步浸轧处理,实现羊毛的生态快速无氯防毡缩整理。选用三羧基乙基膦分别与蛋白酶8.0 T、蛋白酶2.5 L、蛋白酶16 L组成的混合溶液对羊毛纤维进行处理,测试处理后羊毛的断裂强力、断裂伸长、毡缩球密度,借助扫描电子显微镜观察分析处理后羊毛鳞片层的形貌。结果表明,三羧基乙基膦分别与3 种蛋白酶联合处理羊毛的防毡缩效果均显著,且蛋白酶16 L 的防毡缩效果为最佳。通过正交试验优化得出最佳工艺条件：蛋白酶16 L 质量浓度为1.8 g/L,三羧基乙基膦质量浓度为1.0 g/L,处理温度为50 ℃,处理时间为2 min。     

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