石耳多糖的提取工艺研究

采用单因素试验和正交试验设计,探讨提取时间、料液比和提取温度对石耳多糖提取率的影响,筛选出了最佳提取工艺。结果表明,影响石耳多糖提取率的主次因素为料液比、提取温度及提取时间;石耳多糖最佳提取工艺条件为:提取温度80℃,提取时间4h,料液比1∶10。在此工艺条件下,水溶性石耳多糖的提取率为4.63%。     

洋葱水溶性多糖的提取工艺研究

通过正交试验设计以期获得洋葱中水溶性多糖的最佳提取工艺.以新鲜洋葱为原料,采用水提法提取洋葱水溶性多糖,以提取温度、提取时间、料液比扣提取次数为考查因素,比较各因素对洋葱水溶性多糖提取率的影响.结果表明:水提法提取洋葱水溶性多糖的最佳工艺参数为提取时间3.0h,提取温度80℃,液料比1∶12(m∶V),提取次数3次.在该提取条件下洋葱水溶性多糖提取率可达到3.697％.     

正交试验优化山楂多糖提取工艺

本研究采用热水浸提法提取山楂多糖,通过正交试验优化了山楂多糖的提取工艺。实验结果显示,最佳提取工艺条件为:料液比1∶40、浸提时间4h、浸提温度80℃、提取次数3次。在此工艺条件下山楂多糖的提取率达到1.52±0.04%。     

油茶饼粕茶皂素与多糖综合提取工艺

以油茶脱脂饼粕为原料,对其茶皂素和多糖的综合提取工艺进行研究。采用有机溶剂浸提法先提取茶皂素,再提取多糖,并分别采用单因素试验和正交试验探讨其最佳工艺条件。结果表明,提取油茶饼粕皂素的最佳工艺条件为乙醇浓度80%、料液比1:9(g/mL)、提取时间4 h、提取温度90℃,在此条件下茶皂素提取率为8.98%;提取油茶饼粕多糖的最佳工艺条件为提取温度70℃、料液比1:30(g/mL)、提取时间4 h,在此条件下多糖提取率为5.88%。     

东革阿里多糖制备工艺研究

在单因素试验中考察提取温度、提取次数、提取时间和液料比对东革阿里多糖提取率的影响,并运用响应面分析方法进行优化,最终确定了东革阿里多糖的最佳提取工艺,液料比30∶1 (mL/g)、提取温度100℃,提取时间2 h、提取次数3次。采用此工艺,多糖提取率达到4.18%。     

响应曲面法优化枸骨果实多糖提取工艺

为探讨枸骨果实多糖的最佳提取工艺,在单因素试验的基础上,以多糖提取率为响应值,通过Box-Bekxken实验设计和响应面分析建立二次回归模型方程,对影响多糖提取率的3个主要因素:液料比、提取温度、提取时间进行优化,结果显示:枸骨果实多糖提取的最佳工艺条件是提取温度80℃、提取时间1.5 h、液料比150∶1(m L/g)。该工艺参数条件下的枸骨果实多糖的提取率达到28.84%。     

乙醇沉淀法提取葡萄多糖的研究

利用乙醇沉淀法提取葡萄多糖。研究表明此法提取葡萄多糖的最佳条件为:温度90℃,时间2h,料液体积比1∶2,次数为3。在提取液浓缩至原体积1/10的基础上用6倍体积的体积浓度95%乙醇进行沉淀。根据最佳提取工艺可使葡萄多糖的提取率达到99.9%。     

黄蘑多糖提取工艺及纯化研究

采用单因素实验和L9(33)正交实验设计,考察了浸提溶剂、料液比、浸提时间、浸提温度和浸提次数对黄蘑多糖提取率的影响,确定最佳提取工艺。采用Sevage法除蛋白,乙醇反复沉淀,AB-8大孔吸附树脂纯化黄蘑多糖。结果表明:影响多糖提取率的主次因素为浸提时间、浸提温度及料液比;黄蘑多糖最佳提取工艺条件:料液比1∶25,浸提温度90℃,浸提时间3h。在此工艺条件下,黄蘑多糖提取率为30.48%。纯化后的多糖含量为91%,分子量约为104356。     

无花果多糖提取技术研究

以无花果取汁后的残渣为原料,探讨浸提次数、时间、料液比和温度对多糖得率的影响,在单因素试验的基础上,通过正交试验确定最佳提取工艺条件。结果表明:在试验范围内,最佳提取温度为100℃,在此温度下提取次数对多糖提取率影响最大,其次为料液比,提取时间的影响最小。无花果多糖提取的最优条件为提取温度100℃,料液比1:12,浸提2次,每次浸提3h,其水溶性多糖提取率达8.52%。     

响应面法优化苣荬菜多糖提取工艺的研究

以苣荬菜为原料,优化多糖的最佳提取工艺。通过二次通用旋转试验设计方法,研究提取时间、温度、料液比(苣荬菜∶水)对苣荬菜多糖提取的影响。试验结果表明:温度和料液比对提取率有显著影响,其中影响最大的因素是温度,其次是料液比,提取时间对提取效果影响最小。得到了最佳提取工艺参数为:料液比为1∶23,提取温度为92℃,提取时间1.81h,在此条件下进行提取,苣荬菜多糖提取率为1.19%,多糖含量为14.46%。     

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