含茶多酚的大豆分离蛋白涂膜对豇豆保鲜效果的影响

分析大豆分离蛋白与茶多酚对豇豆进行涂膜保鲜的可行性。用茶多酚和大豆分离蛋白复合涂膜液处理豇豆,测定低温(7℃)贮藏过程中呼吸强度、细胞膜相对透性、失重率、叶绿素含量、纤维素含量和维生素C含量等各项指标的变化。涂膜处理可明显降低豇豆的呼吸速率和失重率,减缓了贮藏期间豇豆维生素C与叶绿素含量的下降,对豇豆的纤维化及细胞膜相对透性的上升有明显的抑制作用,且成膜剂大豆分离蛋白中添加茶多酚可进一步增强涂膜处理的效果,和对照相比,5%的大豆分离蛋白溶液中添加200 mg/kg茶多酚制得的涂膜液处理样品可将豇豆的低温保鲜期从6 d延长至12 d。效果显著。大豆分离蛋白中添加茶多酚能够明显延长豇豆的保鲜期。     

茶多酚涂膜对荷兰黄瓜贮藏品质的影响

分析大豆分离蛋白联合茶多酚对荷兰黄瓜进行涂膜保鲜的可行性。以大豆分离蛋白为成膜基质,复合天然抑菌抗氧化物质茶多酚,以感官指标、失重率、叶绿素、可溶性固形物和VC含量为质量指标,定期取样分析测定,探讨不同大豆分离蛋白涂膜复合物在室温条件下对荷兰黄瓜的保鲜效果。结果表明:供试大豆分离蛋白涂膜复合物均不同程度降低了黄瓜的失重率,延缓了黄瓜叶绿素、可溶性固形物和VC含量的下降,可较好地保持贮藏期黄瓜的感官品质。5%的大豆分离蛋白溶液中添加200～300mg/kg茶多酚制得的涂膜液保鲜效果明显,和对照相比,可将荷兰黄瓜的室温保鲜期从5d延长至12d。大豆分离蛋白联合茶多酚能明显延长荷兰黄瓜室温保鲜期。     

涂膜保鲜剂中添加茶多酚对草莓贮藏品质的影响

分析廉价成膜材料大豆分离蛋白与天然抑菌抗氧化物质茶多酚对草莓进行涂膜保鲜的可行性.将茶多酚加入成膜剂中,测定贮藏过程中草莓有机酸、维生素C、可溶性固形物等各项指标的变化.结果表明,涂膜剂中添加茶多酚可明显降低草莓果实的失重率,延缓果实维生素C、有机酸和可溶性固形物含量的下降.涂膜保鲜剂中添加茶多酚量为0.3％保鲜效果最佳,果实的贮藏期延长5d.     

茶多酚联合壳聚糖对黄瓜贮藏品质的影响

分析壳聚糖与天然抑菌抗氧化物质茶多酚对黄瓜进行涂膜保鲜的可行性。用茶多酚和壳聚糖混合液处理黄瓜,结合PE保鲜袋包装贮藏,测定贮藏过程中黄瓜呼吸强度、维生素C含量、硬度及失重率等各项指标的变化。壳聚糖联合茶多酚对黄瓜的保鲜效果优于单一保鲜剂,涂膜剂中添加茶多酚可明显延缓果实呼吸高峰出现的时间、降低黄瓜的失重率,黄瓜的硬度和维生素C的保存率高于对照组。涂膜保鲜剂中添加茶多酚量为0.3%时保鲜效果最佳。壳聚糖中添加茶多酚能够明显延长黄瓜的保鲜期。     

含茶多酚的壳聚糖涂膜对青椒的保鲜效果研究

以壳聚糖为成膜材料,添加天然抑菌抗氧化物质茶多酚,制备青椒复合涂膜保鲜液,以呼吸强度、腐烂率、失重率、VC和叶绿素含量为指标定期取样测定,研究所制成的涂膜液在室温条件下对青椒贮藏品质和生理的影响。结果表明,含茶多酚的壳聚糖涂膜能明显降低青椒在贮藏期间的呼吸强度和失重率,延缓果实VC和叶绿素含量的下降,抑制其腐烂的发生。其中,1.5%的壳聚糖溶液中添加200mg/kg茶多酚制得的涂膜液保鲜效果最显著,和对照相比,青椒的室温保鲜期得以延长。     

含茶多酚的壳聚糖涂膜对四季豆贮藏品质和 生理生化特性的影响

目的研究壳聚糖联合茶多酚对四季豆涂膜保鲜的可行性。方法以四季豆为实验材料,采用壳聚糖涂膜(浓度为1.5%)、壳聚糖联合茶多酚复合涂膜(1.5%壳聚糖中添加150 mg/kg茶多酚)2种保鲜方式,研究茶多酚对四季豆贮藏品质和生理生化特性的影响。结果茶多酚联合壳聚糖涂膜的四季豆在贮藏期内叶绿素、维生素C、水分含量的下降速率和纤维素含量的上升速率均低于壳聚糖涂膜组,贮藏品质较好。茶多酚联合壳聚糖涂膜的四季豆体内的过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的活力低于壳聚糖涂膜组,但二者均高于未处理组。结论涂膜处理有利于四季豆的贮藏,涂膜剂中加入茶多酚后保鲜效果更好,和壳聚糖涂膜相比可将四季豆贮藏期延长10 d,和不涂膜组相比可延长20d。     

大豆分离蛋白/淀粉复合涂膜对青椒的保鲜效果研究

利用大豆分离蛋白/淀粉复合酶处理液对青椒进行涂膜保鲜,测定不同保藏期青椒的呼吸强度、失重率、维生素c含量、叶绿素含量等指标.结果表明,太豆分离蛋白/淀粉复合膜对青椒的涂膜保鲜效果明显.     

茶多酚复合可食性涂膜在香梨保鲜中的应用

本论文研究了库尔勒香梨经过涂膜后的保鲜效果。通过单因素实验分析了可食性涂膜中茶多酚、羧甲基纤维素钠(CMC)、甘油的添加量以及淀粉的种类和含量对香梨失重率的影响,并应用响应面试验对其进行了优化;将香梨涂膜后在30℃干燥45 min,分别在10、20、30 d测其硬度、可溶性固形物、可滴定酸、多酚氧化酶的活性。研究结果表明:30℃贮藏30 d,在100 mL去离子水中加入玉米淀粉5 g时,甘油的添加量是1 g,茶多酚的添加量是3 g,CMC的添加量是0.3 g,涂膜保鲜剂处理的库尔勒香梨失重率为4.33%±0.2%。在贮藏实验中香梨随着贮藏时间的延长,涂膜组比未涂膜组的香梨硬度、可滴定酸含量下降要缓慢,但涂膜组与未涂膜组在可溶性固形物、多酚氧化酶活性的测定实验中数值都呈现上升趋势,涂膜组比未涂膜组上升缓慢。涂膜组在30 d内果实表面完好,而未涂膜组在20 d就已发生腐烂变质。由此说明茶多酚复合可食性膜对香梨有较好的保鲜效果,能有效延长香梨的保鲜期。     

含茶多酚的壳聚糖涂膜对圣女果保鲜效果的影响

将天然抑菌抗氧化剂茶多酚添加到壳聚糖中制成复合涂膜液,以腐烂指数、失重率、有机酸含量、呼吸强度、VC含量为质量指标定期取样测定,研究所制成的涂膜液在室温条件下对圣女果的保鲜效果。结果表明,含茶多酚的壳聚糖膜能明显降低圣女果在贮藏期间的呼吸强度和失重率,延缓果实VC和有机酸含量的下降,抑制圣女果的腐烂速度。其中,2%的壳聚糖水溶液中添加200 mg/kg~300 mg/kg茶多酚制得的涂膜液保鲜效果最显著,和对照相比,可将圣女果的室温保鲜从6 d延长至14 d。     

海藻酸钠和羧甲基纤维素钠涂膜改善鲜切豇豆贮藏特性的比较分析

为了提高鲜切豇豆的品质,本文研究了海藻酸钠(0.6%,m/m)和羧甲基纤维素钠(0.8%,m/m)两种涂膜剂对其贮藏期间的呼吸强度、维生素C、叶绿素等品质指标变化规律的影响。研究发现,与对照相比,在贮藏期间,海藻酸钠和羧甲基纤维素钠涂膜均有效降低鲜切豇豆的呼吸强度,维持较高的可溶性固形物含量,减少鲜切豇豆维生素C和叶绿素的损失,保持较高的过氧化物酶活性,减少丙二醛的积累。贮藏至12 d,海藻酸钠涂膜的鲜切豇豆呼吸强度为237.67 mg/(kg·h),处于较低水平;其维生素C、叶绿素及可溶性固形物含量分别比羧甲基纤维素钠涂膜的高13.06 mg/100 g、0.62 mg/g、0.49%,但丙二醛含量低11.36%。研究结果表明,海藻酸钠涂膜更有利于保持鲜切豇豆的品质及延长贮藏期,其用于豇豆的保鲜贮藏具有潜在的应用前景。     

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