茶树叶片中茶皂素提取工艺优化

以夏季茶树老叶为原料,利用乙醇水溶液提取茶皂素,考察液料比、乙醇体积分数、浸提温度和浸提时间对粗提物中茶皂素含量及茶叶中茶皂素得率的影响。单因素试验结果表明,液料比10︰1(mL/g)、乙醇体积分数70%、浸提温度60℃和浸提时间1.5 h时为宜。通过正交试验确定了茶皂素提取的最佳工艺:液料比20︰1(mL/g)、乙醇体积分数60%、浸提温度70℃、浸提时间2 h。试验结果为夏秋茶资源中茶皂素的提取提供参考。     

泽泻总三萜超声辅助提取工艺优化

以提高泽泻总三萜的提取率为目的,在浸提温度、浸提时间、乙醇体积分数、料液比及超声时间的单因素基础上,采用四因素三水平Box-Behnken响应面试验设计,优选总三萜提取工艺。结果表明:最佳提取条件为乙醇体积分数70%、浸提时间46.00 min,浸提温度57.00℃,料液比1∶14(g/mL),超声时间30 min,该条件下总三萜提取得率为2.98%。     

正丙醇提取茶皂素工艺

采用正丙醇浸提提取油茶籽粕中的茶皂素。考察原料颗粒的目数、浸提液正丙醇溶液的体积分数、料液比、浸提时间、浸提温度以及浸提液pH值对提取效果的影响,并用正交试验获得最佳工艺。以茶皂素得率为优化对象时,最佳工艺为脱脂茶粕60目、80%正丙醇、料液比1:12(g/mL)、温度80℃、时间3h,此条件下,茶皂素得率20.13%、纯度62.78%;以茶皂素纯度为优化对象时,最佳工艺为90%正丙醇、温度80C、脱脂茶粕40目、时间3h、料液比1:11,此条件下,茶皂素纯度72.06%、得率15.31%。上述工艺所得茶皂素产品的得率及纯度均优于常规乙醇浸提法。     

响应面法优化核桃分心木多糖的提取工艺

通过单因素试验研究了浸提温度、浸提时间、料液比和乙醇体积分数4个因素对核桃分心木多糖得率的影响。在此基础上,以多糖得率为响应值,采用响应面法对分心木多糖提取工艺进行优化。结果表明,影响分心木多糖得率的顺序为:浸提时间>乙醇体积分数>浸提温度>料液比;提取核桃分心木多糖的最佳条件为:乙醇体积分数90%,料液比1 g:50 mL,浸提温度95℃,浸提时间156 min。在最佳提取条件下,多糖得率为3.53%,与响应面预测值相差不大。     

超声-微波协同辅助萃取茶皂素

采用超声-微波协同辅助萃取脱脂油茶籽粕中的茶皂素.在单因素试验的基础上,固定超声波功率50 W,萃取次数2次,以乙醇体积分数、料液比、微波功率和萃取时间为影响因素,茶皂素得率为指标,正交试验进行优化,最终确定的茶皂素萃取工艺条件为:乙醇体积分数50％,料液比1∶10,微波功率600W,超声波功率50 W,萃取时间150 s,萃取次数2次.在此条件下,茶皂素得率为(17.43±0.13)％,纯度为67.12％.     

紫色马铃薯花色苷的浸提工艺研究

采用浸提法提取紫色马铃薯中的花色苷,考察了不同溶剂、乙醇体积分数、浸提温度、浸提时间、pH和液料比等因素对浸提效果的影响,确定了最佳单因素水平.通过正交试验,确定了紫色马铃薯中花色苷提取的最佳工艺条件为:乙醇体积分数70%,提取温度50℃,提取时间90 min,pH 1.00,液料比10:1(mL/g).在此条件下,紫色马铃薯中花色苷的一次提取得率为3.4%.液料比和乙醇体积分数是影响紫色马铃薯中花色苷提取率的主要因素,其中,液料比影响最大,达到极显著水平,其次是乙醇体积分数,也达显著水平,时间和温度有一定影响,均不显著.     

茶皂素协同超声辅助提取苦荞芦丁工艺条件的优化

以苦荞芦丁得率为指标，在单因素试验的基础上，运用响应面法对茶皂素协同超声辅助提取苦荞芦丁的工艺进行优化。结果表明：苦荞芦丁的最佳提取工艺为料液比1∶22(g/mL)、茶皂素添加量1.00%(以苦荞粉末质量计)、乙醇体积分数50%、超声时间32 min、提取温度60℃、提取时间80 min,在此条件下，芦丁得率为5.17%;纯化后芦丁的回收率为72.68%,纯度为91.26%。     

油茶饼粕中茶皂素的提取及H2O2法脱色条件研究

通过有机溶剂浸提,研究并确定了从油茶饼粕中提取茶皂素的最佳工艺：乙醇体积分数70％,料液比（g：mL）1：4,提取时间3h,提取温度75％2;H2O2法脱色的最佳条件为pH值8.5,脱色温度70℃,脱色时间2h,加入H2O2 25mL。在此条件下提取的茶皂素得率为17.2％,纯化后的茶皂素质量分数达到87.4％。     

茶叶籽饼粕中茶皂素提取工艺研究

本实验研究了茶叶籽饼粕中茶皂素的浸出工艺。在分析比较不同提取溶剂提取能力的基础上,选择95％乙醇为浸出溶剂,考察了浸提温度、浸提时间、液料比和茶叶籽饼粕粉碎粒度等因素对茶皂素得率的影响。正交试验结果表明,茶皂素提取的较优工艺条件为浸提温度60℃、浸提时间2h、液料比13：1、粒度40目,此时茶皂素得率为8．85％,粗产品茶皂素纯度为54．2％。     

响应面法优化紫苏籽超声辅助提取原花青素工艺研究

为充分利用紫苏资源,优化其籽粕原花青素提取工艺,考察了料液比、乙醇体积分数、超声功率、温度、时间对原花青素得率的影响,并根据Box-Behnken试验设计原理,在单因素试验基础上选择主要影响因素进行响应面试验。响应面优化后提取工艺条件为乙醇体积分数70%、浸提时间0.5 h、浸提温度70 ℃、超声功率100 W、料液比1∶15。在此条件下原花青素得率理论值为0.232%,实测值为0.229%。     

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