响应曲面法优化尼泊金十二醇酯的合成工艺

采用响应曲面优化法(RSM)对尼泊金十二醇酯进行合成制备研究。以氨基磺酸为催化剂,通过该法设计得到了尼泊金十二醇酯合成的最佳工艺:控制十二醇的用量为0.01mol,醇与酸的摩尔投料比为1∶1.2,反应所需温度为100℃,反应所需时长为6h,氨基磺酸的投料量是对酸投料量的10%,酯收率达到94.9%。     

响应面法优化植物甾醇硬脂酸酯制备工艺

采用十二烷基硫酸铜催化合成植物甾醇硬脂酸酯,研究反应温度、反应时间、催化剂用量及酸醇摩尔比等因素对酯化反应的影响。通过单因素试验与响应面试验优化,得出酯化反应的最优制备条件为:反应温度129℃,反应时间2.6h催化剂用量为植物甾醇量1.15%,酸醇摩尔比为1.2∶1,在此条件下制备植物甾醇硬脂酸酯,其酯化率为92.59%。     

响应面法优化大豆油脂肪酸乙酯合成工艺

以大豆油为原料,KOH作催化剂,通过大豆油与乙醇的酯交换反应合成了大豆油脂肪酸乙酯。应用响应曲面分析法中的Box-behnken模型对影响大豆油脂肪酸乙酯转化率的四个主要因素（催化剂用量、醇油摩尔比、反应温度、反应时间）进行了优化。研究表明大豆油脂肪酸乙酯的最佳合成工艺条件为：KOH用量1.3%,醇油比8.3∶1,反应温度74.8℃,反应时间130min。在此条件下,酯转化率达98.93%。     

氨基磺酸催化合成尼泊金十二醇酯

以对羟基苯甲酸与正十二醇为原料,以氨基磺酸为催化剂,以甲苯为溶剂合成尼泊金十二醇酯,其结构经IR得以确证,同时研究了尼泊金十二醇酯合成的最佳条件。结果表明:正十二醇与对羟基苯甲酸摩尔比为1∶1.2,反应温度为100℃,反应时间为6h,氨基磺酸用量为对羟基苯甲酸质量的10%,产率可达94.9%。此法催化剂用量少、催化活性高、反应时间较短、酯收率较高、工艺较简单,是一种绿色、环保、经济、高效的合成尼泊金十二醇酯的方法。     

响应面分析在餐饮废油脂制备生物柴油中的应用

固体超强酸SO42-/Fe2O3为催化剂,餐饮废油脂与甲醇为原料,通过酯交换反应合成生物柴油。以醇油比、反应温度,催化剂用量和反应时间作为影响酯化率的因素,根据Box-Behnken中心组合试验设计原理,采用四因素三水平响应面分析法,依据回归分析确定各工艺条件的主要影响因素。结果表明：生物柴油合成优化工艺条件为：醇油比8.8、反应温度58℃,催化剂用量3.5%、反应时间100min、各因素的主效应关系为：醇油比〉催化剂用量〉反应温度〉反应时间。最佳酯化率的预测值为94.8%,验证值为93.2%。     

活性炭固载磷钨酸催化合成顺丁烯二酸二异辛酯

利用颗粒状活性炭固载磷钨酸和聚乙二醇(400)为混合催化剂，以顺丁烯二酸酐和异辛醇为原料，合成渗透剂T的中间体顺丁烯二酸二异辛酯．研究了反应中的催化剂用量、醇酐量比及反应时间对酯化率的影响．确定了合成该酯的最佳工艺条件为n(醇)：n(酐)：3：1，反应温度为120℃，反应时间为2h．在此条件下酯化率超过95％．此法催化剂用量少，酯化率高，反应时间短，工艺简单．副反应少，无废酸排放，有利于环保。     

棉籽油制备生物柴油技术研究

以棉籽油与甲醇为原料，在催化NaOH存在下，通过酯交换反应制得脂肪酸甲酯，考察了反应条件如醇油摩尔比、催化剂用量、反应温度、反应时间以及原料含水量等的变化对产率的影响，得到棉籽油酯交换反应的最佳反应条件为醇油物质的量比6：1，催化剂用量1．1％，反应温度45℃，反应时间55min。生物柴油的酯交换反应须严格控制原料中的水分。     

强酸性阳离子交换树脂催化合成棕榈酸甲酯

以强酸性阳离子交换树脂为催化剂催化合成棕榈酸甲酯,考察了树脂类型、酸醇物质的量比、反应温度、催化剂用量、脱水剂无水CaCl₂用量、反应时间和催化剂重复使用次数对棕榈酸转化率的影响。结果表明：NKC-9型树脂催化合成棕榈酸甲酯的效果较好;NKC-9型树脂催化反应的最佳条件为：酸醇物质的量比1∶2,反应温度70℃,催化剂用量50%（占棕榈酸质量）,脱水剂无水CaCl₂用量10%（占催化剂质量）,反应时间3 h;在反应的最佳条件下,棕榈酸转化率可达95.36%;催化剂重复使用6次后棕榈酸转化率仍保持在90%以上。     

异构十三醇聚氧乙烯(2)醚的合成

采用酸性催化剂BF3·Et2O合成低环氧加成数的异构十三醇聚氧乙烯醚。研究了催化剂用量、反应温度、反应压力、反应时间对异构十三醇残留量、二烷生成量的影响。确立了较佳的异构十三醇聚氧乙烯(2)醚的反应条件:催化剂用量0.1%,反应温度70℃,反应压力0.2 MPa,反应时间20 min。用气相图谱分析合成的异构十三醇聚氧乙烯(2)醚中原料异构十三醇的残留量为9.8%,二烷的生成量为4.2×10~(-6)。     

纳米无机氧化物催化合成乙酸正丁酯

以冰乙酸和正丁醇为原料,纳米ZnO为催化剂催化合成乙酸正丁酯,探讨催化剂用量、酸醇物质的量比、反应时间等对反应结果的影响,对合成的产物进行红外光谱分析。结果表明,当酸醇物质的量比为1∶2.0,催化剂用量为0.8g(冰乙酸用量为0.1mol),反应温度为91～116℃,反应回流时间为3.0h,其酯化率可达86.72%。     

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