茎用芥菜皮中辛辣风味物质的提取最佳工艺条件研究

目的:从废弃的芥菜皮中提取辛辣风味物质(硫代葡萄糖苷酶解产物异硫氰酸酯),研究其最佳水解条件,为天然调味品生产提供新的原料来源和理论参考。方法:以芥菜皮为原料、水为溶液,采用紫外——可见分光光度法、直接滴定法,通过单因素和正交实验研究芥菜皮中硫代葡萄苷酶解的最佳因素(pH,温度,时间,Vc,料液比)。结论:最佳条件为pH4,温度65℃,时间90min,Vc2mg/g,料液比1∶8,且:pH值>温度>时间>料水比>Vc用量。     

芥菜中硫代葡萄糖苷提取工艺条件的优化

研究了从芥菜中提取硫代葡萄糖苷的最佳工艺条件.选用提取温度、提取时间、料液比(g/mL)及粒度大小作为研究因素,以提取液中硫代葡萄糖苷的含量为考察指标,通过L9(34)正交试验,得到从芥菜中提取硫代葡萄糖苷最佳工艺条件为;提取温度80℃、提取时间20 min、料液比(g/mL)17、原料粒度20目.     

碱法改性玉米种皮不溶性膳食纤维的工艺条件探讨

主要研究碱法改性玉米种皮不溶性膳食纤维的最佳工艺条件.考察pH值、温度、时间及料液比等4个因素对改性后可溶性膳食纤维得率的影响,并在单因素的基础上进行正交试验得到碱法改性玉米种皮不溶性膳食纤维的最佳工艺条件:pH为10、温度为90℃、时间2.5 h和料液比1:50.     

紫薯花色苷提取工艺研究

本文研究了紫薯色素的最佳提取方法以及紫薯色素的稳定性。通过单因素试验对紫薯色素最大吸收波长、最佳提取溶剂、料液比、pH、浸提时间、浸提温度进行探讨,通过料液比、pH、温度三因素三水平试验获取最优提取条件,并对紫薯色素的稳定性做了研究。结果表明,紫甘薯色素的最佳提取条件为:最大吸收波长531nm、最佳提取剂为5%柠檬酸、料液比为1∶100、pH为2、浸提温度60℃、浸提时间1h。色素的颜色和稳定性易受pH值的影响,酸性是较稳定;色素含量易受温度影响,温度升高易使色素降解。正交实验表明:pH为1,料液比1∶50,温度70℃提取效果最好。以上研究结果为紫薯色素的工业化提取及规模化应用奠定了基础。     

碱溶酸沉法提取黑豆蛋白工艺优化

以溶解温度、料液比、pH和溶解时间为因素,以黑豆蛋白提取率为评价指标,在单因素实验基础上,采用响应面优化碱溶酸沉法提取黑豆蛋白工艺条件,结论为:料液比11.93∶1、pH 8.1、温度42℃、时间1.6h。按照最佳条件进行三次验证试验,得最佳提取率为51.88%,与理论转化率(53.21%)相近,相对偏差为2.50%,表明得到的最佳提取条件可靠。其中料液比、溶解温度对提取率的影响显著,其中影响较大的因素为料液比,溶解温度次之。     

正交试验法优化马兰头叶蛋白的提取工艺研究

采用碱提酸沉法从马兰头中提取蛋白质。在单因素试验的基础上,采用L9(34)正交试验设计,研究pH、温度、水解时间和料液比对马兰头蛋白提取率的影响。结果表明,在各影响因素中,影响程度依次为:pH>温度>水解时间>料液比,碱法提取马兰头蛋白的最佳工艺条件为:pH 9.0、提取温度50℃、水解时间60min、料液比1︰25(g/mL),在此条件下测得马兰头蛋白提取率为75.86%。     

莲子蛋白质提取工艺研究

以莲子为原料,研究了料液比、pH值、提取温度、提取时间对莲子蛋白提取率的影响。在单因素试验分析基础上,进行了正交试验,同时考虑到实际操作可行性,最终确定莲子蛋白质最佳提取工艺条件为:料液比1:25,pH11.0,40℃条件下浸提3h,蛋白质提取率为86.45%。     

栀子渣中植物蛋白提取工艺的研究

本实验以栀子渣为原料,采用"碱溶酸沉"原理,通过对料液比、浸提温度、浸提时间及浸提液pH值进行单因素试验,采用L9(34)正交试验对栀子渣中植物蛋白提取工艺条件进行优选。结果表明:浸提液的pH值对植物蛋白提取率的影响程度达到极显著水平,料液比、浸提温度及浸提时间对植物蛋白提取率没有显著影响。栀子渣中植物蛋白提取的最佳工艺条件为:浸提液pH值为9.0、料液比1:20、浸提时间1.5h、浸提温度40℃。     

响应面法优化花椒籽仁蛋白质盐提工艺条件

采用盐提法提取花椒籽仁中蛋白质,探讨提取时间、料液比、NaCl浓度、提取温度、提取pH对蛋白质提取率的影响。在单因素试验的基础上,通过响应面试验优化花椒籽仁蛋白质提取最佳工艺条件。结果表明:固定提取pH为11,其他各因素对花椒籽仁蛋白质提取率的影响次序依次为提取时间提取温度料液比NaCl浓度;最佳提取工艺条件为提取pH 11、提取时间35 min、提取温度50℃、料液比1∶21、NaCl浓度1.2 mol/L;在最佳提取条件下,花椒籽仁蛋白质提取率达到88.77%,所得蛋白质含量达到93.17%。     

玉米胚芽蛋白提取工艺研究

在单因素试验的基础上采用响应面分析方法研究料液比、温度、pH值和时间4个因素对玉米胚芽蛋白提取率的影响。通过中心组合试验设计,建立玉米胚芽蛋白提取数学模型。结果表明,影响玉米胚芽蛋白提取的主要因素依次是pH值、料液比、温度、时间;得到优化组合条件为:料液比1:10、温度55℃、pH10、时间120min。在此工艺条件下,玉米胚芽蛋白最高提取率为34.28%。     

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