胰脂肪酶催化樟树籽仁油和甘油合成中碳链单甘油酯

采用胰脂肪酶催化樟树籽仁油与甘油反应合成中碳链单甘油酯,通过单因素试验和正交试验,研究了反应时间、加酶量、醇油摩尔比、反应初始加水量、反应温度对产物中中碳链单甘油酯含量的影响。结果表明,胰脂肪酶催化樟树籽仁油(10 mL)与甘油反应合成中碳链单甘油酯的适宜条件为:反应温度47℃,加酶量220 mg,醇油摩尔比4.3∶1,反应初始加水量35μL,反应时间30 h。在此反应条件下,产物中中碳链单甘油酯的含量为53.42%±0.05%。     

固体碱催化合成中碳链脂肪酸聚甘油酯

以聚甘油、樟树籽仁油脂肪酸为原料,固体碱KOH/Al2O3为催化剂,催化酯化合成中碳链脂肪酸聚甘油酯.采用单因素试验研究反应温度、反应时间、聚甘油与中碳链脂肪酸质量比、催化剂用量对酯化率的影响,通过正交试验优化中碳链脂肪酸聚甘油酯的合成工艺.最优合成工艺条件为反应温度220℃、反应时间2.5h、聚甘油与中碳链脂肪酸质量比2∶1、催化剂用量4.5％,该条件下酯化率为87.5％,所得中碳链脂肪酸聚甘油酯的酸值(KOH)、皂化值(KOH)、碘值(Ⅰ)、熔点分别为1.86 mg/g、148.4 mg/g、2.9 g/100 g、47.3℃.     

偏甘油酯脂肪酶Lipase G50催化酯化法制备甘油二酯

利用偏甘油酯脂肪酶Lipase G50催化甘油和脂肪酸酯化反应合成甘油二酯.探讨了酶加量、底物摩尔比、反应温度及加水量对酯化反应的影响.结果表明最佳反应条件为:脂肪酶Lipase G50加量为350 U/g,甘油和脂肪酸的摩尔比5∶1,加水量为底物总质量的5％,反应温度30℃,反应时间24h.在最佳反应条件下脂肪酸的酯化率为75.02％,甘油二酯的含量达到44.74％,产物中没有甘油三酯生成.     

酶催化甘油解法制备甘油二酯马油工艺研究

优化酶催化甘油解法制备甘油二酯马油的工艺。以粗马油、甘油为原料,脂肪酶催化合成甘油二酯,采用单因素结合正交试验法,以甘油二酯含量为考察指标,对底物比(粗马油∶甘油)、反应温度、加酶量及反应时间等工艺进行优化,并用CS-9301薄层扫描仪,对甘油二酯进行定性定量检测。结果表明:甘油解法制备甘油二酯马油的最佳条件为粗马油∶甘油(1∶0.5),加酶量为每克粗马油400U脂肪酶,反应时间6h,反应温度40℃,所得甘油二酯马油中甘油二酯的含量达44.18%。     

无溶剂体系中酶促合成中碳链甘三酯

在无溶剂体系下,采用Lipozyme 435催化甘油和中碳链脂肪酸(辛酸和癸酸混合物)酯化合成中碳链甘三酯(MCT).结果表明在无溶剂体系下,反应温度对MCT得率具有显著影响.通过单因素试验和正交试验,得出制备MCT的最佳工艺条件为:反应温度90℃,加酶量(以脂肪酸质量计)5％,底物摩尔比(脂肪酸与甘油摩尔比)3∶1,反应时间16 h.在此条件下,MCT得率为92.10％,产物中甘二酯、甘一酯和游离脂肪酸含量分别为6.03％、0.13％和1.74％.     

樟树籽仁油的结构和特性分析

分别采用气相色谱、液质联用测定分析了樟树籽仁油的脂肪酸组成和分布、甘油三酯组成,测定分析了其理化性质、融化结晶特性。结果表明:樟树籽仁油中所含脂肪酸主要是中碳链脂肪酸,其中癸酸含量为60. 25%、月桂酸含量为35. 88%、辛酸含量为0. 45%,长碳链脂肪酸含量低于5%;樟树籽仁油的甘油三酯组成为CCC(12. 55%)、CCLa(56. 38%)、CLaLa和MCC(20. 36%);樟树籽仁油酸价(KOH)为0. 32 mg/g、皂化值(KOH)为267. 30 mg/g、碘值(I)为5. 70 g/100 g、过氧化值为0. 03 g/100 g;樟树籽仁油的融化温度为21. 63℃、结晶温度为1. 54℃,在人体体温下处于完全融化状态,利于人体吸收代谢。     

延黄牛脂制备高纯度1,3-甘油二酯工艺

目的:提高延黄牛脂的附加值。方法:采用固定化脂肪酶Lipozyme RM IM为催化剂,牛油脂肪酸乙酯(乙醇解法自制)和甘油为原料制备1,3-甘油二酯,运用氢谱考察脂肪酶添加量、底物摩尔比、反应时间以及反应温度对粗反应混合物中1,3-甘油二酯含量的影响,并阐明醇解酯交换前后牛油与甘油二酯产物的脂肪酸组成变化。结果:1,3-甘油二酯合成最佳条件为脂肪酶Lipozyme RM IM质量分数为1%,底物摩尔比(n_{脂肪酸乙酯}∶n_甘油)2∶1,反应时间6 h,反应温度50℃。此条件下的1,3-甘油二酯生成率为72.5%,甘油酯得率为77%;纯化后纯度提高至90.79%。与原油(延黄牛脂)相比,甘油二酯产物中亚油酸和油酸含量分别升高了13.65%,6.47%,饱和度降低了7.17%。结论:延黄牛脂制备1,3-甘油二酯不仅能改变甘油酯结构,还可以改变牛脂的脂肪酸组成,降低其饱和度。     

酶法制备鱼油甘油二酯的研究

以鱼油为原料,研究了各因素对甘油二酯含量的影响。在无溶剂体系中,采用固定化脂肪酶Lipozyme RM IM甘油解法合成甘油二酯,考察反应温度、底物摩尔比(甘油:鱼油)、酶添加量、反应时间对甘油二酯含量的影响。通过响应面设计优化试验条件,确定最佳合成条件为：反应温度50 ℃、酶添加量为底物总质量0.7%、底物摩尔比(甘油:鱼油)为2.3:1、反应时间6 h,甘油二酯质量分数达到48.07%。通过对比粗鱼油与甘油二酯的脂肪酸含量及组成,发现鱼油甘油二酯既可以较好的保持鱼油脂肪酸的组成优势,又可同时具有甘油二酯的特殊营养学特性。     

利用鱼油制备甘油二酯的研究

以鱼油为原料,研究了各因素对甘油二酯含量的影响。在无溶剂体系中,采用固定化脂肪酶Lipozyme RM IM甘油解法合成甘油二酯,考察反应温度、底物摩尔比(甘油:粗鱼油)、酶添加量、反应时间对甘油二酯含量的影响。通过响应面设计优化试验条件,确定最佳合成条件为:反应温度50℃、酶添加量为底物总质量0.7%、底物摩尔比(甘油:粗鱼油)为2.3:1、反应时间6 h,甘油二酯质量分数达到48.07%。通过对比粗鱼油与甘油二酯的脂肪酸含量及组成,发现鱼油甘油二酯既可以较好地保持鱼油脂肪酸的组成优势,又可同时具有甘油二酯的特殊营养学特性。     

酸性离子液体催化合成中碳链甘三酯的研究

在无溶剂体系下,采用离子液体—1-甲基-3-磺丙基咪唑硫酸氢盐[Spmim][HSO4]催化甘油和中碳链脂肪酸(辛酸和癸酸混合物)酯化合成中碳链甘三酯.在单因素实验基础上,采用响应面设计对反应条件进行优化,得到最佳反应条件为:反应温度160℃,反应时间14.03 h,催化剂加入量(以脂肪酸和甘油的总质量计)0.74％,底物摩尔比(脂肪酸与甘油摩尔比)3.2∶1.在最佳工艺条件下,中碳链甘三酯的得率为92.90％,酯化率为95.48％,产物中甘二酯、甘一酯和游离脂肪酸含量分别为2.38％、0.21％和4.51％.     

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