浒苔多糖脱蛋白工艺的考察

研究浒苔多糖的脱蛋白方法与工艺。以蛋白脱除率和多糖损失率作为为指标比较三氯乙酸(TCA)法、Sevag法、酶法及酶-Sevag法脱蛋白的效果。结果表明:酶-Sevag法脱蛋白效果较好,其最佳工艺条件为:酶用量3%,酶解时间3 h,酶解温度45℃,pH 5.0,Sevag法脱蛋白次数2次,在此条件下,蛋白质脱除率和多糖损失率分别为89.73%和27.46%。酶-Sevag法是去除浒苔粗多糖中蛋白质较理想的方法,该优化工艺可用于浒苔粗多糖的脱蛋白。     

玉竹多糖纯化工艺的优化研究

选择合适的玉竹多糖脱蛋白方法进行单因素实验与正交实验,得出最优脱蛋白条件;在此基础上,对比不同类型的树脂对玉竹多糖的脱色效果,选出最适合玉竹多糖脱色的树脂类型及最优动态参数。实验结果表明酶法与sevag法联用为最佳的脱蛋白方法,在酶用量0.1 g,酶解温度40℃,酶解时间1 h,p H为5的条件下,玉竹多糖的脱蛋白效果最好,蛋白质脱除率为72.43%,多糖损失率为13.14%;对玉竹多糖脱色效果好的是大孔阴离子交换树脂脱色1号,上样浓度为4 mg/m L,上样速率为1 m L/min,上样量为2 BV条件下,玉竹多糖的脱色效果最好,脱色率达到80.65%,多糖保留率达到87.82%。     

葡萄多糖脱蛋白方法的研究

采用Sevag法、酶法、酶法与Sevag法结合3种方法对葡萄多糖脱蛋白进行了研究.结果表明:酶用量0.14%,pH6.5,处理温度60℃,处理时间为2h,再用Sevag法脱蛋白4次,此时蛋白脱除率为72.14%多糖损失率为10.91%.因此,酶法与Sevag法结合是取代常规方法脱蛋白的一种有效方法,此法可以有效的脱除游离蛋白,并使多糖损失率最小.     

粪鬼伞多糖脱蛋白方法的研究

探讨粪鬼伞多糖提取过程中的脱蛋白方法与工艺.以蛋白质去除率和多糖损失率为考察指标,比较Sevag法、酶法、三氯乙酸法、酶-Sevag法脱蛋白效果.结果表明,酶-Sevag法脱蛋白效果较好且多糖得率较高,脱蛋白的最佳工艺条件为:酶用量2%,温度40 ℃,脱蛋白时间2 h,pH值5.0;Sevag试剂浓度20%,脱蛋白次数3次,在此条件下,蛋白质去除率和多糖损失率分别为70.95%和6.58%.     

树脂吸附对巴戟天多糖脱色脱蛋白的工艺研究

以脱色率、多糖保留率及脱蛋白率为指标,筛选合适的树脂对巴戟天多糖脱色脱蛋白,并进行静态及动态的工艺研究。确定最佳的工艺条件是:采用D941树脂,室温下(25℃),巴戟天多糖液pH值5.96(原液),以流速2 BV/h进行动态吸附。在此工艺条件下,脱色率为89.87%,多糖保留率81.08%,脱蛋白率50.75%,表明D941树脂具有良好的脱色效果和一定的脱蛋白能力。     

米糠多糖的脱蛋白研究

采用Sevag法、三氯乙酸法和酶法对米糠多糖进行脱蛋白研究.结果表明,酶法脱除蛋白的效果最好,Sevag法的多糖损失较小,结合酶法和Serag法脱蛋白可大大提高蛋白脱除率,具体操作条件为:0.0055mg/mL木瓜蛋白酶、pH6.0、60℃水浴,再加入总体积为1/2的氯仿-正丁醇(2:1)溶液进行脱蛋白,重复操作4次,此时蛋白脱除率为71.23%.多糖损失率为17.38%.     

黑木耳多糖几种脱蛋白方法的对比研究

以黑木耳多糖为对象,比较Savage法、三氯乙酸法、Savage法联合三氯乙酸法、四种树脂静态吸附及动态吸附法对脱蛋白的效果,筛选出最佳的脱蛋白方法及条件:以多糖保留率与蛋白质脱除率为指标,考察选取最佳的脱蛋白方法;通过单因素试验确定黑木耳多糖最佳脱蛋白条件。结果表明,以D3520大孔树脂吸附法效果为最佳,其中蛋白脱除率为79.56%,多糖保留率为81.34%。研究表明D3520对黑木耳多糖的蛋白脱除率和多糖保留率均较高,可用于黑木耳多糖的蛋白脱除工序。     

碱提菜籽多糖脱蛋白方法的研究

采用5种方法对碱提菜籽多糖进行脱蛋白处理,结果表明:酶法-Sevag法联用的方法可以有效的脱除游离蛋白并使多糖损失较小,其最佳的条件,酶用量为0.12%,反应温度为60℃,反应时间为45min,Sevag法脱蛋白的次数为3次。经过最佳条件脱蛋白,蛋白的脱除率为74.8%,多糖损失率为21.6%。     

微波辅助提取花生粕多糖的五种脱蛋白方法研究

通过微波辅助提取法从花生粕中提取多糖,从而探索花生粕多糖脱蛋白的最优方法。以蛋白质脱除率和多糖损失率为指标,比较Sevag法、三氯乙酸法、木瓜蛋白酶法、木瓜蛋白酶–Sevag联用法和木瓜蛋白酶–TCA联用法脱除花生粕多糖蛋白的效果。结果显示:木瓜蛋白酶–TCA联用法效果最好,其脱蛋白的最佳条件为木瓜蛋白酶用量0.05 g、酶解温度45℃、酶解反应2 h,采用6%TCA溶液除蛋白1次,此时蛋白去除率为85.83%,多糖损失率为6.44%。     

啤酒花多糖的提取及脱蛋白工艺研究

以超临界液态二氧化碳萃取后的啤酒花残渣为原料,采用正交实验和单因素实验,确定了啤酒花多糖的热水微波辅助萃取的最佳工艺条件:提取时间2h,料液比1∶10,提取温度90℃,微波功率750W作用时间12min;此条件下多糖提取率为2.76%。对得到的粗多糖,以蛋白脱除率和多糖保留率为指标,在比较Sevag法,盐酸-正丁醇法,三氯乙酸-正丁醇法,木瓜/菠萝蛋白酶法对粗多糖中蛋白质的脱除效果的基础上,考察了酶法和化学法联用脱蛋白工艺,并最终确定菠萝蛋白酶-三氯乙酸-正丁醇的脱蛋白效果最好,最佳条件为温度45℃,酶解时间0.5h,酶添加量22.5U/mL,pH5.5,三氯乙酸-正丁醇法除蛋白1次,蛋白脱除率和多糖保留率分别为86.77%和77.37%;而木瓜蛋白酶-盐酸-正丁醇的脱蛋白工艺在有效脱除蛋白质的同时,多糖损失最少,最佳条件为温度55℃,酶解时间0.5h,酶添加量36U/mL,pH5.5,盐酸-正丁醇法除蛋白1次,蛋白脱除率和多糖保留率分别为77.37%和84.43%。     

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