超声波辅助提取花生白藜芦醇工艺研究

以花生根为原料,采用二次通用旋转组合试验设计,探讨超声波提取花生根白藜芦醇的最佳工艺参数.研究结果表明:最佳工艺条件为乙醇浓度75%,超声功率290 W,萃取时间5.5 min,液料比18:1,白藜芦醇得率为(3.96±0.01)‰.乙醇浓度、料液比可极显著影响提取得率,超声功率、提取时间则影响显著提取得率,其中影响最大的是乙醇浓度,其料液比、萃取时间和超声功率.     

黄金茶中总黄酮超声提取工艺

对超声法提取黄金茶中总黄酮的工艺进行优化。利用超声法提取黄金茶中的总黄酮,考察了超声时间、超声功率、乙醇浓度、料液比4个因素对总黄酮得率的影响,通过单因素试验和正交试验确定了提取的最佳提取工艺条件。最佳提取工艺为超声时间20min,超声功率75W,乙醇浓度70%,料液比1∶20(g/mL),总黄酮得率为5.3493%。     

响应面法优化超声辅助提取八角黄酮工艺研究

探讨八角黄酮超声辅助乙醇水二元体系最优提取工艺条件。考察了乙醇浓度、超声时间、料液比和超声功率等因素对八角黄酮得率的影响,通过响应面优化提高黄酮得率的超声提取条件。结果表明:乙醇浓度、超声时间、料液比和超声功率等显著影响总黄酮得率。优化出提高八角黄酮得率的最佳超声提取工艺:乙醇浓度73%,超声时间23min,料液比1∶45,在此条件下黄酮得率为9.43%±0.13%。     

超声波辅助提取梵净山黑茶多酚工艺的优化

在单因素试验的基础上,选取料液比、乙醇浓度、超声功率、超声时间利用正交试验优化超声波辅助提取梵净山黑茶多酚的工艺。试验结果表明,影响黑茶多酚提取率的主要因素依次为超声时间、乙醇浓度、料液比、超声功率。通过分析得出:料液比1∶12(g/m L)、乙醇浓度60%、超声功率350 W、超声时间40 min为最佳提取条件。对最佳提取条件进行验证,得出梵净山黑茶多酚提取率为7.22%。     

杜仲叶总黄酮的超声提取工艺

利用超声法对杜仲叶中总黄酮的提取工艺进行研究。单因素考察超声功率、超声时间、乙醇浓度、料液比、提取次数等因素对总黄酮得率的影响,并用正交试验对总黄酮的提取工艺条件进行优化。结果表明,杜仲叶总黄酮最佳提取工艺条件为:超声功率600 W,超声时间30 min,乙醇浓度60%,料液比1∶15(g/mL),提取2次,在最佳条件下总黄酮得率为2.04%。     

大肉姜总黄酮的超声波提取工艺

研究了贺州大肉姜中黄酮类化合的超声波提取条件,通过单因素试验分析了超声时间、超声温度、乙醇浓度、超声功率、固液比、提取次数对总黄酮的影响,采用正交实验优化了提取工艺,结果表明,提取大肉姜黄酮的最佳提取工艺为超声时间50 min、超声温度55 ℃、乙醇浓度60%、超声功率为70 W、固液比1:30、提取次数为2次.经测定贺州大肉姜总黄酮含量为18.40 mg/g.     

穿心莲总黄酮微波辅助提取工艺的研究

通过单因素、正交实验及其方差分析探索微波辅助萃取法提取穿心莲黄酮类化合物的最佳工艺条件,采用紫外分光光度法测定总黄酮含量.结果表明影响实验因素的主次顺序是:乙醇浓度＞固液比＞微波作用功率＞微波作用时间,其中乙醇浓度、功率、固液比对总黄酮的提取都有显著影响.最佳提取工艺为微波功率处于高火、微波作用时间6min、固液比1:...     

超声波辅助提取黄花菜中多酚类物质工艺的优化

探索超声波提取黄花菜中多酚类物质的最佳工艺条件。以没食子酸标准品为参比计算出多酚类物质的含量,选取超声功率、料液比、乙醇浓度、超声时间进行正交实验,对正交实验结果进行方差分析和多重比较。结果表明:影响黄花菜中多酚类物质提取得率的主要因素依次是料液比、乙醇浓度、超声时间和超声功率;通过方差分析可知,料液比、乙醇浓度、超声时间这三个因素差异都极显著,超声功率差异不显著。通过多重比较得出:超声功率为120W、料液比为1∶20、乙醇浓度为90%、超声时间为40min时为最佳提取条件,得出黄花菜多酚类物质提取得率为2.975%。      

小麦麸皮总黄酮超声提取工艺研究

以小麦麸皮为原料,乙醇为提取溶剂,对超声波辅助提取小麦麸皮总黄酮工艺进行研究。考察了超声功率、提取时间、乙醇浓度、料液比、提取次数等因素对小麦麸皮总黄酮得率的影响,并通过正交试验对总黄酮的提取工艺进行优化。结果表明,小麦麸皮总黄酮最佳提取工艺为:超声功率600 W,提取时间30 min,乙醇浓度60%,料液比1∶20,提取两次,在最佳条件下总黄酮得率为2.29%。     

响应面法优化超声提取芝麻叶黄酮的研究

采用响应面分析方法优化芝麻叶中黄酮化合物的超声辅助提取条件.利用中心组合设计研究乙醇浓度、液固比、超声提取时间、超声功率4个自变量对响应值黄酮得率的影响.用SAS 8.1进行结果分析.响应面的典型分析可知稳定点是最大值.决定系数为0.9007.分析回归系数可知：乙醇浓度对响应值的影响极其显著（p＜0.001）.黄酮最佳提取工艺条件为：乙醇浓度56%,液固比：25∶1,超声提取时间36 min,超声功率：330 W,在此条件下黄酮得率为3.460%.     

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