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不同温度和包装方式对荔枝保鲜品质的影响 总被引:6,自引:1,他引:5
为掌握温度和包装对荔枝货架期的影响,本试验以“淮枝”荔枝为试验材料,以裸露的荔枝和由开孔袋包装的荔枝,分别处于常温货架和低温货架,研究不同因素对荔枝质量损失率、褐变指数、好果率、色差、可溶性固形物含量和可滴定酸含量的影响。试验表明:低温货架和包装都能延长荔枝货架期,各品质指标整体衰变速度从快到慢依次为:常温裸露、常温包装、低温裸露、低温包装。对荔枝货架期影响因素中,温度占主要影响作用,低温货架有效的降低了荔枝各指标的变质速度;开孔聚乙烯薄膜包装也能降低荔枝品质的衰变,该影响小于货架温度的影响。常温货架无包装的荔枝好果率在30 h变为0,低温包装荔枝的好果率在60 h仍保有9.20%。与常温货架荔枝裸露的销售方式对比,采用低温货架并由开孔聚乙烯薄膜包装可以使荔枝货架期延长一倍以上。该文为荔枝货架期保鲜研究提供了参考。 相似文献
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目的 研究李果实采后品质变化及建立李果实采后货架期预测模型。方法 本试验设置了3种温度(4、15、25℃),并定期测定生理生化指标。采用零级动力学模型和一级动力学模型结合Arrhenius方程建立基于品质变化的李果实采后货架期预测模型,并验证模型的预测精确度。结果 低温明显延缓了果皮强度和果肉硬度的下降和果实失重率的上升,同时也延缓了花色苷含量的积累,对总酸含量影响不明显。根据果皮强度、果肉硬度和失重率变化建立货架期预测模型,通过验证发现基于失重率变化的货架期预测模型具有最好的精确度,相对误差值低于10%。结论 货架期预测模型的建立,可快速预测果实剩余货架期,为贮藏和货架提供技术指导。 相似文献
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采用货架期加速试验方法和Arrhenius方程建立猪油曲奇饼干的货架期预测模型。以过氧化值为指标,在试验储藏条件下(25,35,45,55℃),猪油曲奇饼干的过氧化值随储藏时间的变化符合一级品质劣变动力学模型。研究了加速储藏条件下的样品检测重复次数、检测点数和检测时间间隔对货架期预测模型预测精度的影响。结果表明:测定点数对预测精度的影响最大,其次是测定重复次数,影响最小的是测定时间间隔。不同温度下的速率常数以及结合Arrhenius方程建立了猪油曲奇饼干的货架期预测模型,该模型对25℃下猪油曲奇饼干货架寿命具有较好的预测效果,预测误差为-2.74%,具有一定的应用价值。 相似文献
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以坛子肉半成品为试验材料,经2450MHz,12kW的微波设备在80℃进行杀菌3min后,探究不同贮藏温度(4℃,10℃,25℃,37℃)对贮藏期间坛子肉的感官品质、pH值、挥发性盐基氮、过氧化值、菌落总数的的影响及指标间的相关性,结合回归方程及方差分析构建货架期预测模型。结果表明:贮藏温度与感官品质、挥发性盐基氮、过氧化值、菌落总数相关性极显著;经温度和货架期预测回归方程求出在4℃,10℃,25℃和37℃下货架期分别为422.15d、374.43d、255.14d和159.70d,经验证预测货架期和实际货架期间相对误差为1.87-8.53%,该货架期预测模型效果优良。 相似文献
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为探讨油炸裹糊牡蛎的货架寿命,以感官评分、pH、挥发性盐基氮(total volatile basic nitrogen, TVB-N)含量、菌落总数为指标,研究在4、15、25 ℃下贮藏的油炸裹糊牡蛎的品质变化规律,建立并验证油炸裹糊牡蛎在4~25 ℃贮藏温度下的货架期预测模型。结果表明:随贮藏时间的延长,油炸裹糊牡蛎的感官评分不断下降,pH呈先下降后上升的趋势,TVB-N含量和菌落总数不断增加,且贮藏温度越高,变化越快。感官评分与TVB-N含量的相关性较pH与菌落总数的高,以TVB-N含量作为关键品质指标,建立的油炸裹糊牡蛎货架期预测模型预测的货架期相对误差小于6%,可用于快速准确地预测4~25 ℃贮藏温度下油炸裹糊牡蛎的货架寿命。 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