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对淀粉质原料中的粗淀粉含量的测定,按传统分析法,水解时间就需3h,全部分析工作需要4h左右,即费时又耗能源,为此,根据酸解原理,试验采用20%的盐酸溶液,用量为50ml,经30min水解,所测得的原料淀粉含量与传统分析法基本相当。现作以下介绍。l试验材料费林试剂甲液:称取69.3g硫酸铜,用水溶解并稀释到1000ml;乙液:称取3469酒石酸钾钠,1009氢氧化钠,用水溶解并稀释到10O0ml;2%盐酸溶液:望取4.sml浓盐酸,用95.sml水稀释;15%盐酸溶液:量取15ml浓盐酸,缓慢倒入85ml水中;20%盐酸溶液:里取20ml浓盐酸,缓慢倒入80ml水… 相似文献
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采用响应面分析方法研究了酶法水解大米蛋白制取持水剂的工艺条件,并对产品应用于香肠中的水分活度降低效果进行了试验。试验结果表明:酶法水解大米蛋白制取持水剂的优化工艺参数为:对10%的大米蛋白乳液400mL,反应温度为45.6℃、反应时间为4.84h、酶与底物浓度比为528μ/g。经优化工艺条件制得持水剂的水分活度为0.856,所对应的水解度为33.7%。在香肠中添加4.0%的持水剂,其降低水分活度的效果与添加1.0%食盐所产生的效果相当。 相似文献
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酱油生产过程中,豆粕水解条件的选择对后续的微生物发酵,酱油风味及成本具有重要影响。本文对盐酸浓度、水解时间和温度对水解过程的影响作了研究。实验结果表明:适当啬盐酸浓度、延长水解时间以及升高水解温度,能提高酱油的全氮利用率,氨基酸氮含量,改善酱油风味,降低成本,在90℃左右,5% ̄9%盐酸浓度下水解30 ̄35h,能得到品质优良的酱油。 相似文献
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酶法水解麦胚制取持水剂的研究 总被引:1,自引:0,他引:1
采用响应面分析方法研究了酶法水解麦胚制取持水剂的生产工艺,并对产品应用于香肠中的抗氧化效果进行了试验。试验结果表明:酶法水解麦胚制取持水剂的优化工艺参数为:对10%的麦胚乳400ml,反应温度为44.4℃,反应时间为4h,酶与底物浓度比为860μ/g。经优化工艺生产的持水剂的水分活度为0.896,所对应的水解度为26.5%。应用于香肠可显著提高其货架寿命。 相似文献
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利用碱性蛋白酶对破壁后的油松花粉进行水解以提高油松花粉蛋白的水溶性,将油松花粉中的蛋白质转化成肽的形式.以水提取液中的氮溶指数为指标,确定制取油松花粉肽的最适宜水解条件:温度为50℃,pH 为 10.0,底物浓度为 4.5%,酶浓度为 4000 u/g,水解时间为 2 h.在此条件下,水解液的氮溶指数为 80.30%. 相似文献
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松香酰基复合氨基酸表面活性剂的合成研究 总被引:3,自引:0,他引:3
以菜籽粕和松香为原料,经菜籽粕的水解,松香酰氯化和缩合反应等合成了N-松香酰复合氨基酸表面活性剂。实验结果表明,松香与三氯化磷反应制取松香酰氯的收率在85%以上,菜籽粕用60mol/L的盐酸在105℃-110℃下水解18h制得复合氨基酸溶液,氨基酸得率为89%,松香酰氯与复合氨基酸进行缩合反应合成了松香酰基复合氨基酸,通过正交回归试验确立的最佳工艺条件为松香酰氯与氨基酸摩尔配比为1.38:1,反应温度22℃,反应时间4.78h,pH7-8,以丙酮/水(v/v)1:1为混合溶剂,转化率达到85.3%,合成产品具有良好的表面活性。 相似文献
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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. 相似文献
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John Gilbert Catherine Simoneau David Cote Achim Boenke 《Food Additives & Contaminants》2000,17(10):889-893
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. 相似文献
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Sophie Guillot Laurence Peytavi Sylvie Bureau Renaud Boulanger Jean-Paul Lepoutre Jean Crouzet Sabine Schorr-Galindo 《Food chemistry》2006
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. 相似文献
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Jesus Simal-Gandara Miguel Sarria-Vidal Arjen Koorevaar Rinus Rijk 《Food Additives & Contaminants》2000,17(8):703-711
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. 相似文献
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M. S. Garcí a-Falc n J. Simal-G ndara S. T. Carril-Gonz lez-Barros 《Food Additives & Contaminants》2000,17(12):957-964
A simple, rapid and inexpensive method has been developed for the determination of benzo[a 相似文献
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H. J. Van Den Top A. Boenke P. A. Burdaspal J. Bustos H. P. Van Egmond T. Legarda A. Mesego A. Mourino W. E. Paulsch C. Salgado 《Food Additives & Contaminants》2001,18(9):810-824
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. 相似文献
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《肉类研究》2014,(2)
<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 相似文献
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《印刷工业》2014,(11):95-95
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%. 相似文献
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《印刷工业》2014,(8):103-103
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 相似文献