季铵盐修饰壳聚糖及其复合膜的制备与表征

该研究以季铵盐对壳聚糖进行修饰改性,利用单因素实验分析了壳聚糖季铵盐的最优制备条件,通过傅里叶红外光谱、核磁氢谱对其结构进行了表征;并探究不同取代度的壳聚糖季铵盐制备的涂膜的机械性能;以壳聚糖季铵盐为原料,引入聚乙烯醇,纳米二氧化钛,丙三醇,采用溶液共混法制备了壳聚糖季铵盐复合膜,并通过傅里叶红外光谱、热重分析以及接触角对壳聚糖季铵盐复合涂膜的结构、性能进行分析。结果表明,壳聚糖季铵盐的最优制备条件为季铵盐与壳聚糖的质量比为3:1,反应时长为12 h,反应温度为80 ℃。此外,当壳聚糖季铵盐含量为50%（以聚乙烯醇为标准）,纳米二氧化钛含量为1%,丙三醇含量为0.8%时,壳聚糖季铵盐复合膜的拉伸强度和断裂伸长率取得最优值,分别为19.38 MPa和55.78%。相应的壳聚糖季铵盐复合膜（19.38 MPa）的拉伸强度较壳聚糖复合膜（18.64 MPa）也高,这说明壳聚糖季铵盐的改性有利于增加涂膜的机械性能,为后续研究壳聚糖改性膜材料提供了一定的理论参考。     

壳聚糖／壳寡糖衍生物的制备及其抗氧化性能研究

壳聚糖和壳寡糖经化学改性得到季铵盐衍生物-O-2′-羟丙基三甲基氯化铵壳聚糖/壳寡糖,通过红外光谱对其结构进行表征.考察了两种季铵盐衍生物对DPPH自由基的清除活性以及还原能力.当质量浓度为0.6 mg/mL时,壳聚糖季铵盐和壳寡糖季铵盐对DPPH自由基的清除率分别为9.5 %和29.3 %.在还原体系中,当质量浓度为2.5 mg/mL时,其吸光度分别为0.11和0.43.结果表明:通过化学改性,得到的壳聚糖季铵盐衍生物水溶性优良、具有抗氧化活性;壳寡糖季铵盐清除自由基的活性和还原能力强于壳聚糖季铵盐衍生物.这可能由于壳寡糖分子链短,更多活性氨基和羟基暴露出来参与抗氧化反应所致.     

壳聚糖季铵盐改性棉织物的无盐染色工艺研究

利用壳聚糖和2,3-环氧丙基三甲基氯化铵制备壳聚糖季铵盐对棉针织物进行改性,分析壳聚糖季铵盐的结构特征,探讨壳聚糖季铵盐改性棉针织物预处理工艺中改性剂壳聚糖季铵盐的用量、浸渍时间和浸渍温度对染料上染百分率和K/S值的影响。结果表明,壳聚糖季铵盐改性棉针织物的最佳工艺为:壳聚糖季铵盐浓度8 g/L、浸渍时间60 min、浸渍温度70℃、浴比1∶30;经壳聚糖季铵盐改性后棉织物能够实现活性染料的无盐染色,织物具有较好的耐洗、耐摩擦色牢度,满足服用需求。     

季铵盐化羧甲基壳聚糖处理对棉纤维结构和性能的影响

采用超声波辅助法,合成O-羧甲基壳聚糖及季铵盐化羧甲基壳聚糖。通过对处理后试样的增重率、扫描电镜、红外光谱、X射线衍射、热重、强伸率、耐磨性、抗皱性进行分析,研究了棉纤维经季铵盐化羧甲基壳聚糖处理后结构和性能的变化规律。结果表明,季铵盐化羧甲基壳聚糖与棉纤维发生交联反应,但不会引起纤维内部结晶度的明显变化,结晶度仅提高1.49%,断裂强度提高41 N,耐磨次数提高4次,急弹性折皱回复角提高28.8°,缓弹性折皱回复角提高33.1°。通过季铵盐化羧甲基壳聚糖处理棉纤维后,其结构和性能得到了一定程度的改善,这为棉纤维的后续改性和进一步加工提供了一定的研究基础。     

季铵盐壳聚糖/聚乙烯醇复合膜的制备及性能研究

壳聚糖为天然多糖甲壳素脱除部分乙酰基的产物,因其独特的生理功能,能满足很多的应用要求。但由于其水溶性不是很好,在生理pH 6.0以下时溶解度较低,因此限制了壳聚糖在涂膜保鲜上的应用。该研究以季铵盐对壳聚糖进行修饰改性,通过傅里叶红外光谱、核磁氢谱、X-射线衍射对其结构进行表征,并探究不同取代度的季铵盐壳聚糖制备的涂膜的机械性能,最后以季铵盐壳聚糖为原料,采用溶液共混法制备7种不同体积比的季铵盐壳聚糖/聚乙烯醇复合膜,并通过傅里叶红外光谱、热重分析、扫描电镜、水蒸气透过率分析、机械性能测试对复合膜的结构、性能进行分析。得到最佳的复合膜制备体积比,此时复合膜的性能与单纯的聚乙烯醇膜和季铵盐壳聚糖膜相比表现出突出的优越性。复合膜拉伸强度为16.52 MPa,断裂延伸率为56.55%,结晶度为34.60%,水蒸气透过率为98.71 g/（m2·h）,涂膜的最大失重速率为83.20%,最大失重速率温度为347.21℃。该文为后续壳聚糖改性膜材料研究提供了一定的理论参考。     

反应性壳聚糖季铵盐的合成及其在柞丝绸抗菌整理上的应用

为提高壳聚糖的水溶性,并增强其与纤维之间的结合力,采用壳聚糖与2,3-环氧丙基三甲基氯化铵反应, 合成了水溶性的2-羟丙基三甲基氯化铵壳聚糖(壳聚糖季铵盐),再将壳聚糖季铵盐与N-羟甲基丙烯酰胺进一步反应,合成了带有纤维反应性基团的水溶性O-甲基丙烯酰胺壳聚糖季铵盐（反应性壳聚糖季铵盐）,用傅里叶红外光谱表征了所合成的壳聚糖季铵盐、反应性壳聚糖季铵盐和处理前后柞蚕丝的结构, 研究了经反应性壳聚糖季铵盐整理后柞丝绸的抗菌性能。结果表明：经整理的柞丝绸洗涤20次后,对金黄色葡萄球菌和大肠杆菌的抑菌率均高于90%。     

O-羧甲基化壳聚糖季铵盐的制备及抑菌活性

目的：制备抑菌活性较壳聚糖强的水溶性壳聚糖衍生物。方法：以3-氯-2-羟丙基三甲基氯化铵(CTA)和氯乙酸为接枝改性剂,制备水溶性O-羧甲基化壳聚糖季铵盐,采用红外光谱和紫外光谱对其结构进行表征,并研究O-羧甲基化壳聚糖季铵盐对大肠杆菌(E.coli)、金黄色葡萄球菌(S.aureus)和黑曲霉(A.niger)的抑制作用。结果：水溶性的O-羧甲基化壳聚糖季铵盐对E.coli、S.aureus和A.niger均有显著的抑菌活性。结论：与壳聚糖相比,水溶性的O-羧甲基化壳聚糖季铵盐的抑菌活性提高。     

新型多羟基壳聚糖季胺盐的合成

探讨了由三乙醇胺与环氧氯丙烷制备季胺盐中间体的工艺因素(反应温度、时间及投料比)，并采用所得中间体对壳聚糖进行改性，且利用FT-IR对合成的新型多羟基壳聚糖季铵盐进行了分析。     

壳聚糖季铵盐的合成及其对糖浆的澄清作用

本文介绍对壳聚糖的改性合成,得到水溶性良好的壳聚糖季铵盐;对产物的红外测试、1H-NMR测试及取代度测定证明:在壳聚糖的C2位氨基上发生了季铵盐的取代.改性产物与壳聚糖相比,水溶性得到改善,对糖液的澄清效果有所提高,当对固溶物用量为100 ppm时,其脱色率分别提高34%(420 nm)及28%(560 nm).     

季铵盐改性壳聚糖/壳寡糖及其在纺织领域的应用

介绍了壳聚糖的结构特点以及壳聚糖季铵盐和壳寡糖季铵盐的性能特点,并介绍了壳聚糖/壳寡糖季铵化改性的研究进展。指出了目前国内壳聚糖及壳寡糖季铵盐在纺织领域的应用研究现状和应用中的不足。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press