季铵盐改性聚硅氧烷微乳液的半连续共聚法

以八甲基环四硅氧烷（D4）和甲基二乙氧基硅丙基二甲基十八烷基氯化铵（GS-18）为原料,AEO 7和AEO 9为乳化剂,十二烷基苯磺酸（DBSA）为催化剂,采用半连续乳液聚合法制备了阴离子 非离子复合型季铵盐改性聚硅氧烷(QAMP)微乳液。试验考察了催化剂DBSA含量、反应温度、预乳液滴加时间、非离子复合乳化剂（NCS）用量、D4含量和硅氧烷季铵盐含量对微乳液透光率的影响。结果表明,在一定范围内,微乳液的透光率随DBSA含量和非离子乳化剂用量的增加、反应温度的升高及预乳液滴加时间的延长而变大,随D4含量和硅氧烷季铵盐含量的增加而降低。当m(NCS)/m(D-4)和m(DBSA)/m(D4)都为0.3,聚合温度为75 ℃,预乳液的滴加时间为2 h时,可制备有机硅含量为20%,有机硅季铵盐含量1.5%（相对于D4的质量）,透光率为92%的微乳液,其对涤纶布有较好的整理效果。     

毛用亲水性有机硅柔软剂的合成及应用

用壬基酚聚氧乙烯醚(OP-10)作乳化剂,以十二烷基苯磺酸(DBSA)为催化剂,通过八甲基环四硅氧烷(D4)开环聚合,在一定条件下合成了阴离子有机硅微乳液.而后对其进行氨基、聚醚改性合成了毛用亲水性有机硅柔软剂.D4、OP-10、DBSA用量分别为微乳液质量的20%,4%～5%,3%～4%,60～70℃恒温反应5 h,预乳液滴加时间为1.5～2.0 h;改性剂用量为单体量的5%,聚醚、氨基改性剂质量比为1.5:1,反应温度为60～65℃,恒温反应2 h.合成的有机硅柔软剂为乳白半透明液体,略泛蓝光.结果表明,该产品不仅能使处理过的织物具有优良的柔软性和白度,并且还能赋予织物良好的亲水性.     

低温化学法合成β-谷甾醇亚麻酸酯

在无溶剂条件下利用酸性催化剂4-十二烷基苯磺酸（DBSA）催化β-谷甾醇与亚麻酸酯化合成β-谷甾醇亚麻酸酯,通过单因素试验和响应面法优化了酯化反应条件,并采用红外光谱对产物结构进行了表征。结果表明,最佳酯化反应条件为反应温度76 ℃,反应时间12 h,醇酸摩尔比1∶ 1.7,DBSA用量16%。在最佳条件下,β-谷甾醇转化率高达97.55%。红外光谱测试结果表明目标产物成功合成,实现了低温化学法合成β-谷甾醇亚麻酸酯。     

乙烯基改性聚硅氧烷乳液的制备

以八甲基环四硅氧烷(D4)与乙烯基三乙氧基硅氧烷(A-151)为单体,十二烷基硫酸钠(SDS)和脂肪醇聚氧乙烯醚(AEO9)为复合乳化剂,十二烷基苯磺酸作催化剂,制备了性能稳定的乙烯基改性聚硅氧烷乳液.讨论了乳化剂、催化剂、硅烷偶联剂用量,反应温度,反应时间等因素对聚合反应的影响.结果表明:当乳化剂用量4％(对单体总质量),催化剂用量8％(对D4质量),硅烷偶联剂用量5％(对D4质量),反应温度75℃,反应时间3h时,所得聚合物乳液的稳定性较好,单体转化率也比较高.     

环氧双封端硅油的合成

以八甲基环四硅氧烷(D4)、端环氧双封头(F2D2)为原料,在四甲基氢氧化铵(TMAH)的催化作用下,合成了环氧双封端硅油.研究了反应物配比、反应温度、反应时间及催化剂用量对产品性能的影响,并用红外光谱对产物进行了结构表征.结果表明:当预先设定n(D4)∶n(F2D2)=20∶1时,最佳反应温度为110℃,反应时间为4.5 h,催化剂用量为0.045%,合成的环氧双封端硅油粘度为380m Pa·s,环氧值为0.019 0 mol/100 g,D4转化率为80.98%.并在最佳反应温度、反应时间、催化剂用量下,选取不同的反应物配比,合成出一系列不同分子质量的环氧双封端硅油,用以制备不同用途的三元共聚有机硅.     

D72型树脂催化合成邻苯二甲酸二甲酯

用D72型阳离子交换树脂作为苯酐与甲醇反应合成邻苯二甲酸二甲酯的催化剂，研究了催化剂的用量、物料配比、反应温度、反应时间等因素对酯化反应的影响．结果表明：当催化剂的质量分数为4％，n(苯酐)：n(甲醇)：1：3，反应温度为110℃，反应时间为6h时，反应的酯化率可达99％。     

微乳体系中脂肪酶催化棕榈酸制备生物柴油及其工艺优化

以十二烷基苯磺酸(Dodecyl benzenesulfonic acid,DBSA)+TX-100/环己烷/1-丁基-3-甲基咪唑四氟硼酸盐(Bmim BF_4)微乳体系为反应介质,Candida rugosa脂肪酶为催化剂,进行棕榈酸与乙醇酯化反应制备生物柴油,并考察离子液体用量、醇酸摩尔比、脂肪酶用量、反应温度、反应时间等因素对棕榈酸乙酯产率的影响。在单因素实验的基础上,根据中心组合Box-Benhnken实验设计原理,采用响应面分析法对生物柴油制备工艺进行优化。结果表明生物柴油制备的最佳工艺条件为:离子液体Bmim BF_4用量30%,醇酸摩尔比6.3∶1,脂肪酶用量为棕榈酸质量的14%,反应温度34℃时,反应时间3.0 h,此条件下,棕榈酸乙酯的产率为97.5%,该结果与模型预测值基本相符。     

双端乙烯基聚硅氧烷的合成及其改性聚丙烯酸酯的性能

以八甲基环四硅氧烷(D4)和1,3-二乙烯基-1,1,3,3-四甲基二硅氧烷(DVMS)为原料,三氟甲基磺酸为催化剂,通过阳离子开环聚合合成双端乙烯基聚硅氧烷(di Vi-PDMS),并以其改性聚丙烯酸酯,用于涂料印花。研究了催化剂用量、反应温度和反应时间对有机硅单体总转化率和合成产物di Vi-PDMS双键封端率的影响,并对di Vi-PDMS结构和相对分子质量进行表征,测定di Vi-PDMS改性聚丙烯酸酯胶膜及涂料的印花性能。结果表明:当催化剂用量0.15%,反应温度70℃,反应时间6 h,有机硅单体总转化率达91%;改变n(D4)∶n(DVMS),可合成出相对分子质量为2 000~20 000的di Vi-PDMS;di Vi-PDMS改性聚丙烯酸酯胶膜水接触角为98.50°,吸水率为7.39%,断裂延伸率、断裂强度分别为1 160%、2.65 MPa;其印花织物的耐干/湿摩擦色牢度达4级,手感柔软。     

吗啉型氨基硅油的合成工艺及应用研究

采用酌-氯丙基甲基二甲氧基硅烷、吗啉、D4为原料,以四甲基氢氧化铵为催化剂,经过胺化、开环聚合反应制备了以吗啉为官能基团的硅油柔软剂,对影响反应因素进行了考察,确定了最佳工艺条件,并对其应用性能作了探讨.结果表明:在催化剂用量1×10-4～3×10-4(对单体质量)、反应温度110～160℃、反应时间6h条件下,得到含叔胺的吗啉型氨基硅油的氨值0.6mmol/g,白度86.1%.     

乙烯基聚硅氧烷低聚物乳液的制备及应用

以八甲基环四硅氧烷(D4)与γ-甲基丙烯氧基丙基甲基二甲氧基硅烷(KH-571)为主要原料,采用乳液聚合法制得乙烯基聚硅氧烷低聚物乳液,将其应用于丙烯酸酯乳液的改性.优化了低聚物的聚合工艺,并进行了结构表征,结果表明:w(KH-571)=10%、w(催化剂DBSA)=10%、w(复合乳化剂)=3%,80℃下保温反应4~6 h,制备出稳定性较好、平均粒径50.0 nm且粒径分布较窄、最高转化率为89.4%的乳液.FT-IR表明得到乙烯基聚硅氧烷低聚物.用低聚物改性丙烯酸酯乳液,可得到平均粒径100.0 nm且分布较窄,乳液凝胶率低于4.0%,稳定性较好的硅丙乳液.     

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.     

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.     

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.     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.