非晶颗粒态玉米淀粉的制备及接枝共聚改性

以玉米淀粉为原料,采用乙醇溶剂一高温加热制备了非晶颗粒态玉米淀粉,通过X-射线衍射和偏光显微镜研究了非晶颗粒态玉米淀粉的结晶性质与颗粒形貌;以中和的丙烯酸为单体,过硫酸铵为引发剂,N,N'-亚甲基双丙烯酰胺为交联剂,对非晶颗粒态玉米淀粉进行接枝共聚改性,制备出具有高吸水性的接枝共聚物,并对其吸水性能做了研究,其吸水率和吸盐水(0.1%NaCl)率分别为590.1g/g和232.6 g/g;用扫描电子显微镜、红外光谱对其进行结构表征.     

复合空心纳米粒子PAA@Fe_3O_4的制备及药物控释研究

在反尖晶石型空心磁性Fe3O4纳米粒子表面修饰上APTES,然后通过化学交联法包覆上聚丙烯酸(PAA)制备了p H敏感性PAA@Fe3O4复合空心纳米粒子。用透射电子显微镜(TEM)、振动样品磁强计(VSM)、纳米粒度仪、傅里叶变换红外光谱仪和紫外分光光度计对包覆前后的形貌、结构、磁性和包覆率进行表征。并用罗丹明6G(R6G)作为模拟药物进行药物负载和释放性能进行体外实验研究。结果表明,所制备的PAA@Fe3O4复合粒子具有良好的磁学性能,负载药物为1011 mg/g。复合磁粒上的R6G药物释放的最大释放比达到93.0%,这种药物控释属于一级释放曲线,同时探讨了基于分子溶解度的可能机理。这种基于磁性纳米粒子和高分子材料的复合药物负载体系,有助于提高药物的靶向递送性能并改善诊疗效率。     

静电纺壳寡糖-月桂酸共聚物/聚乙烯醇蓄热调温纳米纤维工艺优化

为了制备具有抗菌、蓄热调温双重功能的纳米纤维膜,采用接枝聚合方法制备了壳寡糖-月桂酸接枝共聚物(COS-LA),并添加到静电纺丝溶液中,制备了聚乙烯醇(PVA)/COS-LA纳米纤维膜。通过傅里叶变化红外光谱、扫描电镜、差示扫描量热法表征COS-LA共聚物、纳米纤维膜的表面形貌、化学结构及热性能。结果表明：壳寡糖与月桂酸接枝成功,PVA/COS-LA复合纺丝溶液可纺性良好,制备的PVA/COS-LA纳米纤维直径均匀,分布规整;当共聚物COS-LA质量分数为8%时,纳米纤维膜蓄热调温性能较好,热吸收峰区间为37.65℃～51.25℃,热焓值为29.14 J/g。     

半纤维素基pH响应性水凝胶的制备及其药物控释研究

以从玉米芯中提取的水不溶性半纤维素(wis-AGX)(中性单糖组成为:83. 09%木糖、10. 03%葡萄糖、4. 76%阿拉伯糖、0. 76%半乳糖)为原料,在碱性介质中与丙烯酰胺接枝共聚并适度水解,在半纤维素中引入具有pH响应性的聚丙烯酸(PAA)链段,再将共聚物与聚乙烯醇(PVA)溶液共混后以戊二醛交联制备半纤维素基水凝胶。通过核磁共振仪和傅里叶变换红外光谱仪对该水凝胶的化学结构进行表征,利用扫描电子显微镜对水凝胶的形貌特征进行表征,研究了该水凝胶在去离子水和不同pH值环境下的溶胀行为。结果表明,水凝胶具有明显的pH响应性,且在pH值10时溶胀率最高,可达1210%。此外,水凝胶的溶胀率与羧基含量正相关,与戊二醛用量负相关。以茶碱作为模型药物,探讨了其在模拟胃液(pH值1. 2)和肠液(pH值7. 4)介质中的药物释放行为。在6 h内,担载药物后的水凝胶在模拟肠液中的药物累积释放量可达68%,明显高于其在胃液中51%的药物累积释放量,故此水凝胶有明显的药物缓释作用。     

氨基功能化有机-无机杂化介孔材料合成及药物释放性能研究

以1,2-二(三甲氧基硅基)乙烷(BTME)和3-氨基丙基三乙氧基硅烷(AMPTS)为前驱体,通过共缩聚的方法合成氨基修饰的乙烷桥联的有序介孔氧化硅,并对其进行表征;再以布洛芬为模型药物,将得到的材料用于药物的吸附与释放,研究其药物释放性能.结果表明,氨基修饰后的杂化介孔材料对布洛芬具有更强的吸附能力,从修饰前的0.35 g/g增加至0.78 g/g.与未修饰的材料EA—0相比,氨基功能的材料EA—20在释放过程中具有更好的缓释效果.     

阳离子瓜尔胶与丙烯酰胺接枝共聚物的制备研究

以硝酸铈铵(CAN)为引发剂,采用水溶液聚合法,制备了阳离子瓜尔胶与丙烯酰胺的接枝共聚物(pAAm-g-CG40)。研究了引发剂浓度、单体浓度、反应温度以及反应时间等因素对接枝反应的影响,当CG40浓度为10g/L,硝酸铈铵浓度为3 mmol/L,丙烯酰胺浓度为0.7mol/L,反应温度和时间分别为50℃和4h时,接枝率和接枝效率达最大值。并对接枝共聚物进行红外谱图分析,证实了接枝反应的发生。     

微波辐射淀粉接枝共聚物研究

以玉米淀粉为主要原料,以N,N'-亚甲基双丙烯酰胺为交联剂,过硫酸钾为引发剂.以丙烯酸为淀粉接枝单体对微波辐射合成淀粉接枝共聚物反应条件进行优化研究,并对共聚物结构进行了分析.研究结果表明:在m(淀粉):m(丙烯酸)=1:5,pH 6.8,初始聚合温度35℃～40℃时.合适的接枝共聚反应条件为:引发剂和交联剂用量(与单体质量百分比)分别为O.1%和0.008%.微波功率280 W,时间180 s,此时合成的树脂吸水率为772.9 g/g.通过红外扫描可知共聚物存在着羧基、酰胺基等特征性亲水性基团.     

反相微乳液法制备芭蕉芋淀粉接枝丙烯酸盐共聚物

在氮气保护的环境下,以过硫酸铵为引发剂、N,N＇-亚甲基双丙烯酰胺为交联剂,采用反相微乳液法制备芭蕉芋淀粉接枝丙烯酸盐共聚物;确定含芭蕉芋淀粉的稳定反相微乳液体系的制备工艺：油水比为1.2:1、复合乳化剂用量为30%、乳化剂的亲水亲油平衡值(hydrophile lipophylic balance,HLB)为7.36;利用正交试验法优化利用反相微乳液法制备淀粉接枝丙烯酸盐共聚物的工艺条件,在最佳工艺(单体丙烯酸的用量16mL、引发剂用量3.5%、交联剂用量0.8%、单体丙烯酸中和度70%)条件下,制备出芭蕉芋淀粉接枝丙烯酸盐共聚物的吸水倍率可达1340g/g。红外光谱分析结果表明,聚合过程中芭蕉芋淀粉与丙烯酸发生了接枝共聚反应。     

淀粉纳米颗粒的醇沉法制备与同步包埋山奈酚的研究

以木薯淀粉为原料,通过超声波搅拌制备淀粉纳米颗粒,采用扫描电镜、激光纳米粒度仪、X-射线衍射进行表征。在淀粉纳米颗粒的沉降阶段中,以0.7 mg/mL的山奈酚醇溶液作为非溶剂相,同步对山奈酚包埋,制备山奈酚淀粉纳米颗粒。探索乙醇浓度对山奈酚包埋率的影响,考察包埋体系对山奈酚释放率和稳定性的影响。结果表明,乙醇浓度在60%时形成淀粉纳米颗粒,形貌较好,尺寸均匀分布在50～200 nm之间;乙醇浓度低于40%时生成V型淀粉颗粒。乙醇浓度为30%时,山奈酚的包埋率最高,可达62.94%,包埋量为3.78 mg/g;在模拟体液环境中,山奈酚淀粉纳米颗粒可持续释药20 h,释药率为88.75%,而山奈酚原药在3 h基本释放完全,释放率为93.75%,且释放速率随缓释介质的乙醇浓度升高而加快。相对山奈酚水溶液,山奈酚淀粉纳米颗粒在室温下静置5 h,山奈酚的保留率由43.17%提高至75%,具有稳定的包埋作用。由此可知,同步包埋制备技术对山奈酚具有良好的包埋缓释效果和稳定作用。     

电纺制备耐水性聚乙烯醇/聚丙烯酸纳米纤维膜及其吸附性能研究

采用静电纺丝技术和热交联技术制备了PVA/PAA50 000和PVA/PAA450 000两种纳米纤维膜,检测了它们的力学性能和对染料甲基蓝(MB-yl)和亚甲基蓝(MB-ylene)的吸附性能。PVA/PAA纳米纤维膜具有较大的拉伸强度,对MB-ylene具有良好的选择性,吸附机理遵循Langmuir等温吸附模型和准二级动力学方程,吸附过程具有自发性。经过5次脱附再生实验,PVA/PAA纳米纤维膜对MB-ylene染料的去除率约为90%,说明该材料具有良好的脱附再生性能。     

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