相转移剂存在下大豆油脂肪酸单甘脂的合成

以大豆油和甘油为原料,研究了碱催化下大豆油甘油解生成脂肪酸单甘脂的合成反应。同时,利用单因素试验对影响单甘脂质量分数的几种重要因素(如反应温度、催化剂、相转移剂、碱用量、反应时间、反应物料物质的量比)进行讨论,通过正交试验,确定了制备大豆油脂肪酸单甘酯的最佳工艺条件:甘油与大豆油物质的量比为2.5∶1,0.4%的NaOH为催化剂,辅以0.4%的四丁基溴化铵为相转移催化剂,于反应温度200℃下反应时间3 h,得到单甘酯的质量分数为62.6%,为单甘脂的合成提供了一种改进的方法。     

单甘酯与缩水甘油反应制备高纯度低聚甘油脂肪酸酯的研究

本文对单甘酯与缩水甘油反应制备高纯度低聚甘油脂肪酸酯进行研究,分别探讨催化剂及其用量、反应温度、反应时间、底物摩尔比值对低聚甘油酯产率的影响。通过单因素试验对各参数进行优化,在以苯磺酸作为催化剂、添加量1.5wt%、反应温度110℃、反应时间2h、底物摩尔比值(缩水甘油∶单甘酯)2.5∶1的最优条件下,低聚甘油酯产率为62.59%,经分子蒸馏进一步纯化获得高纯度的低聚甘油酯产品(91.45%),且以低聚甘油单酯为主要成分。     

碱性白土催化甘油三酯甘油解制备单甘酯的研究

为提高单甘酯的产率,采用自制碱性白土为固体碱催化剂催化甘油三酯甘油解制备单甘酯。通过XRD、FTIR对碱性白土进行了结构分析。同时采用4因素3水平的Box-Behnken实验设计和响应面以及matlab软件进行实验的条件优化。以自制碱性白土为催化剂时,适宜的反应条件为：反应时间为38.91min,反应温度为266.8℃,催化剂用量为0.981g/100g三酯,甘油与三酯的摩尔比为8.91。此时单甘酯产率为74.97%。此外,碱性白土较Ca(OH)₂具有产品颜色浅,二甘油含量少的优点。     

自生压条件下三种催化剂对红花油脂肪酸二聚作用的影响

以红花油为原料,皂化酸解后得到复合脂肪酸。研究了在自生压条件下,蒙脱土、高岭土和二氧化锆3种催化剂对红花油复合脂肪酸二聚作用的影响。结果表明,在加料量140mL(脂肪酸与反应容器的体积比为0.47)、加水量2%、搅拌速度550r/min的条件下,红花油脂肪酸二聚化制备二聚酸的适宜条件为:(1)催化剂蒙脱土的用量9%,催化助剂Li2CO3用量0.6%,反应温度280℃,反应时间4h,产率74.99%;(2)催化剂高岭土用量9%,催化助剂Li2CO3用量0.5%,反应温度280℃,反应时间5h,产率72.16%;(3)催化剂二氧化锆用量7%,催化助剂Li2CO3用量0.7%,反应温度260℃,反应时间5h,产率为67.49%。     

固体超强酸催化大豆油和大豆油脂肪酸酯化与酯交换制备单甘酯的研究

采用固体超强酸催化大豆油和大豆油脂肪酸与甘油酯化和酯交换制备单甘酯,通过二级分子蒸馏纯化单甘酯。通过响应面优化得到的最佳条件为：大豆油30.0 g,大豆油脂肪酸20.0 g,反应温度200℃,固体超强酸催化剂添加量0.26%（占大豆油和大豆油脂肪酸质量）,甘油添加量12.66 g和反应时间4.81 h。在最佳条件下,反应得到的甘油酯混合物中,单甘酯含量达到69.82%。甘油酯混合物在Ⅰ级135℃分子蒸馏除去游离脂肪酸和甘油,在Ⅱ级185℃分子蒸馏蒸出单甘酯,得到产品中单甘酯含量为96.54%。     

蔗糖酯型表面活性剂的合成工艺研究

以天然棉籽油,制糖厂的副产品乙醇来制取棉籽油脂肪酸乙酯,进一步通过棉籽油脂肪酸乙酯与蔗糖进行均相熔融酯交换反应生成蔗糖脂肪酸酯。以配料比、皂用量、催化剂用量、反应温度、反应时间构建了五因子四水平正交试验,通过产率、单酯含量和亲水亲油平衡(HLB)值的结果分析,确定了蔗糖棉籽油脂肪酸酯的最佳合成方案:蔗糖∶脂肪酸乙酯=1∶0.8;催化剂用量为2%;皂用量为15%;反应温度控制在135℃;反应时间为2h,在此基础上进行了单因素影响延伸试验,确定各影响因素的影响程度及顺序。     

自生压条件下三种催化剂对红花油脂肪酸二聚作用的影响

以红花油为原料，皂化酸解后得到复合脂肪酸。研究了在自生压条件下，蒙脱土、高岭土和二氧化锆3种催化剂对红花油复合脂肪酸二聚作用的影响。结果表明，在加料量140mL（脂肪酸与反应容器的体积比为0．47）、加水量2％、搅拌速度550r／min的条件下，红花油脂肪酸二聚化制备二聚酸的适宜条件为：（1）催化剂蒙脱土的用量9％，催化助剂Li2CO3用量0．6％，反应温度280℃，反应时间4h，产率74．99％；（2）催化剂高岭土用量9％，催化助剂Li2CO3用量0．5％，反应温度280℃，反应时间5h，产率72．16％；（3）催化剂二氧化锆用量7％，催化助剂Li2CO3用量0．7％，反应温度260℃，反应时间5h，产率为67．49％。     

固体超强酸催化合成月桂酸单甘酯的研究

以固体超强酸Nafion-H为催化剂,研究无溶剂条件下月桂酸和甘油直接酯化合成月桂酸单甘酯。考察了影响合成月桂酸单甘酯的因素,实验结果表明反应最适宜工艺条件为:月桂酸/甘油物质的量比为1∶2.5,反应温度为190℃,反应时间为2 h,催化剂为月桂酸和甘油总质量的1.5%,月桂酸单甘酯含量达到64.1%。催化剂无须任何处理即可重复使用,有好的工业应用前景。     

固定化脂肪酶催化合成单甘酯

研究了蛋壳作载体固定化脂肪酶催化棕榈油甘油解合成单甘酯的最佳工艺条件：反应温度28℃,甘油水含量4%,甘油与油脂摩尔比4:1,固定化酶用量为110U/g棕榈油,反应平衡时间24h,单甘酯最高含量44.2%。产率为83%,考察了固定化酶催化合成的稳定性,使用6次后固定化脂肪酶活力仍保留70%。     

废弃油脂甘油酯化降酸过程中的甘油聚合研究

基于甘油酯化降酸的优势和降酸过程甘油聚合的问题,开展了废弃油脂甘油酯化降酸过程中甘油聚合的研究。考察了反应温度、甘油用量、催化剂种类、催化剂用量对甘油聚合的影响,并分析了聚甘油的聚合度。结果表明:反应温度越高、甘油与脂肪酸摩尔比越大,降酸速率越快,甘油聚合率越高,在反应温度220℃、甘油与脂肪酸摩尔比1∶1时甘油聚合率约为33.8%;聚甘油主要为二聚甘油;甘油酯化过程引入锌基催化剂,不仅提高降酸速率,缩短反应时间,还能降低反应温度、减少甘油的聚合,从而提高副产物甘油的回收率;与催化剂Zn Cl_2、Zn(Ac)_2相比,催化剂Zn O效果最好,在Zn O用量0.3%、反应温度180℃、甘油与脂肪酸摩尔比1∶1时甘油聚合率可降至约13%。研究结果将有助于进一步优化甘油酯化降酸工艺,为甘油酯化耦合碱催化酯交换法制备生物柴油技术的设计提供参考。     

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