低沸点有机溶剂结合水蒸汽法提取孜然精油研究

实验采用低沸点有机溶剂结合水蒸汽法对孜然精油进行提取,分别研究了提取温度、提取时间、粒度和液料比对孜然油树脂提取率的影响,同时还研究了利用水蒸汽从所提的油树脂中分离出精油的条件,结果表明,油树脂提取最佳参数组合为:浸提温度33℃,浸提时间8h,原料粒度70目,液料比4.5∶1,此时精油得率为4.87%,达到了预期的结果。      

乙醇法提取黑胡椒油树脂的研究

设计正交试验研究乙醇法提取黑胡椒油树脂的工艺条件,考查了乙醇浓度、料液比、浸提温度、浸提时间以及原料粒度对黑胡椒油树脂提取率的影响。试验结果表明：在乙醇浓度为85％,原料粒度为80目,料液比为1：10（g／mL）,浸提时间为3．5h,浸提温度为65℃工艺条件下,黑胡椒油树脂提取率为10．32％。     

黑胡椒油树脂乙醇浸提工艺研究

采用响应曲面法优化黑胡椒油树脂乙醇浸提工艺,考察提取温度、提取时间、料液比和黑胡椒原料粒度对黑胡椒油树脂得率的影响,并分析黑胡椒油树脂中胡椒碱含量。结果表明:黑胡椒油树脂的最佳浸提条件为温度56℃,浸提时间8h,料液比1∶16.6(g/mL),粒度90目。在此条件下,黑胡椒油树脂得率为10.86%,黑胡椒油树脂中胡椒碱含量为38.73%,验证试验与模型预测值基本相符。     

大蒜精油树脂的提取工艺研究

从大蒜头中提取精油树脂的工艺条件进行了系统的研究。首先比较了几种不同的有机溶剂浸提效果,结果表明,石油醚是一种较佳的浸提剂。用石油醚浸提提取大蒜头中大蒜精油树脂,探讨了浸提温度,浸提时间,搅拌时间,料液比等因素对大蒜精油树脂提取效果的影响,通过L9(34)正交试验确定了最佳工艺参数,结果显示:浸提温度25℃,浸泡时间2 d,每2 h搅拌40 min,料液比1∶3。     

微波辅助水蒸汽蒸馏法和无溶剂微波萃取法提取孜然精油工艺的研究

采用微波蒸馏法提取孜然精油,考察微波溶剂提取和无溶剂提取孜然精油工艺中微波提取时间、微波功率、粒度和液料比等因素对孜然精油提取率的影响。同时以枯茗醛含量作为精油品质的评价指标,并通过GC对孜然精油进行分析。研究结果表明,微波溶剂提取孜然精油的最佳工艺条件为：液料比6:1、微波提取时间90min、微波功率300W,此条件下精油提取率为3.501%,精油中枯茗醛含量为19.121%。微波无溶剂提取孜然精油的最佳工艺条件为：浸泡时间30min、微波提取时间45min、微波功率200W,此条件下精油提取率为2.461%,精油中枯茗醛含量为23.910%。     

超声波辅助水蒸汽蒸馏法提取地椒精油工艺的研究

以榆林市卧云山地区地椒为实验材料,采用超声波辅助水蒸汽蒸馏法对地椒精油的提取工艺进行了研究。以地椒精油得率为指标,在单因素实验基础上,研究提取时间、料水比、浸提温度以及超声功率4个因素对地椒精油得率的影响,并通过正交实验得出最佳提取条件。实验结果表明:影响地椒精油得率的四个因素的主次顺序为:超声功率>浸提温度>提取时间>料水比,最佳提取条件为:提取时间40 min,液料比20∶1(m L∶g),浸提温度45℃,超声功率200 W;三次验证实验表明,地椒精油得率高达0.901%±0.1%。此种提取方法可为地椒精油在实际生产中提供一定的理论参考。      

孜然精油及其熟制精油的研究

利用超临界CO₂萃取技术提取孜然精油,通过研究原料粒度、萃取压力、萃取温度、萃取时间等因素对孜然油萃取率及品值的影响,确定超临界CO₂萃取最佳工艺参数。另外,采用熟化工艺对孜然原料进行前处理再利用超临界CO₂萃取技术提取,获得具有熟香风味的熟制孜然精油。研究结果表明,超临界CO₂萃取孜然油的最佳工艺参数为:原料粒度30目,萃取压力30MPa,萃取温度60℃,萃取时间2.5h,精油得率约为13.97%,精油中枯茗醛质量分数高达32.75%。熟制孜然精油熟化工艺中最佳焙烤温度为180℃,超临界CO₂最佳萃取条件为原料粒度30目,萃取压力25MPa,萃取温度60℃,萃取时间2.5h,精油得率约为11.38%,精油中枯茗醛质量分数高达31.95%。     

复合溶剂提取大蒜精油的工艺条件研究

以环已烷- 丙酮复合溶剂提取大蒜精油,对复合溶剂提取大蒜精油的工艺条件进行研究,探讨影响大蒜精油得率的因素条件：复合溶剂质量配比、料液质量比、浸提温度、浸提时间。单因素试验确定较好的因素水平,正交试验确定最佳提取工艺条件。结果表明,提取大蒜精油最佳工艺条件为：环已烷- 丙酮复合溶剂质量配比7:3,料液质量比1:6,浸提温度55℃,浸提时间6h。     

狗枣猕猴桃叶黄酮提取工艺的研究

以乙醇作为提取剂,采用振荡提取法从狗枣猕猴桃叶中提取黄酮类化合物,研究了乙醇浓度、样品粒度、料液比、浸提温度、浸提时间及浸提次数对提取效果的影响。结果表明,料液比对黄酮提取效果影响最大,其次为提取时间和提取温度,而样品粒度和乙醇浓度影响较小。狗枣猕猴桃叶黄酮的最佳提取工艺条件为:乙醇浓度75%,粒度80目,料液比1∶15,浸提温度80℃,浸提时间2h,浸提次数3次,在此条件下黄酮提取率可达7.250%。     

圆葱中精油及黄酮类提取工艺研究

研究了提取溶剂种类、浸提温度、浸提时间、料液比等对圆葱精油及黄酮提取率的影响。试验表明,选择乙酸乙酯作为提取溶剂,料液比为1∶1.25(g∶mL),浸提温度40℃,浸提时间120min时圆葱精油提取率可达到0.19%;在超声波辅助萃取圆葱皮中总黄酮的研究中,乙醇浓度80%,料液比1∶10(g∶mL),超声温度40℃,超声时间15min时提取率最高。     

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