预冷方式及MAP贮藏对芦笋采后生理变化的影响

为探讨预冷方式及MAP贮藏对芦笋保鲜的效果,以绿芦笋为试材,研究了真空、冰水、冷库自然预冷等3种不同的预冷方式并结合低温MAP处理对采后生理、营养品质和感官质量的影响.结果表明芦笋采后未经及时预冷、未用MAP包装入库,贮藏8 d的芦笋因营养品质和感官质量急剧下降而失去商品价值;真空预冷的降温速度最快并能显著降低芦笋的呼吸强度;采用低温并结合MAP包装处理,能有效降低细胞膜透性和粗纤维含量的增加,抑制维生素C和叶绿素含量的下降,芦笋贮藏20d仍具有较好的感官质量与商品价值.预冷对芦笋的贮藏效果依次为真空预冷、冰水预冷和冷库自然预冷.     

芥末精油复合1-甲基环丙烯保鲜处理对绿花菜贮藏期间品质的影响

该实验以绿花菜（Brassica oleracea var. italica）为研究对象,采用1-甲基环丙烯（1-Methylcyclopropene,1-MCP）、芥末精油（Mustard essential oil,MEO）、1-MCP处理复合芥末精油（1-MCP+MEO）对新鲜绿花菜进行保鲜处理,通过感官品质、相对电导率、叶绿素、维生素C、丙二醛含量等生理生化指标的测定,考察其对绿花菜贮藏期间品质的影响。结果表明：随着贮藏时间的增加,各组保鲜剂处理均能够有效地维持绿花菜贮藏期间的品质,其中1-MCP+MEO处理对绿花菜贮藏效果最优,有效地维持了绿花菜外观,避免了黄变和霉斑的出现,减缓叶绿素含量和维生素C降解速率,使绿花菜的叶绿素含量始终高于其他处理组。1-MCP+MEO能够抑制绿花菜的相对电导率和丙二醛（Malondialdehyde,MDA）含量上升。贮藏第28 d时,复合处理组的相对电导率和丙二醛分别为14.94%和9.1μmol/g,比对照组少了43.1%和27.6%,且存在显著性差异（P<0.05）,使得绿花菜细胞保持较好的完整性,从而抑制绿花菜的衰老。贮藏28 d...     

低温对自发气调包装鸡毛菜保鲜效果的影响

为研究低温对采后鸡毛菜保鲜效果的影响,将鸡毛菜进行自发气调包装,然后在0、4、8、12℃下贮藏,通过测定贮藏期间感官品质、电导率、叶绿素、VC、菌落总数等来比较不同贮藏温度的保鲜效果。结果表明:0℃下贮藏的鸡毛菜保鲜质量最好,有效地维持了鸡毛菜的感官品质,减缓了鸡毛菜维生素C的氧化分解,同时有效抑制了鸡毛菜腐败变质和叶绿素的损失。     

真空预冷及贮藏方式对生菜品质的影响

为了提高生菜的真空预冷及保鲜效果,采用不预冷+25℃贮藏、不预冷+6℃贮藏、真空喷水预冷+6℃贮藏以及真空喷CaCl2溶液+6℃贮藏4种方式,从感官品质、失重率、叶绿素含量及维生素C含量四个方面研究了不同预冷和贮藏方式对采后新鲜生菜品质的影响。结果表明:生菜采收后,感官品质、叶绿素和维生素C含量均随贮藏时间的延长而下降,失重率上升。真空预冷前喷洒0.5%浓度的CaCl2溶液+6℃贮藏的方法既能补充真空预冷过程中的水分损失,又能延长生菜的贮藏期,减缓生菜的失重率增长、叶绿素和维生素C含量的降低,是一种能将快速预冷和保鲜贮藏结合起来,且省时有效的好方法,为探寻预冷保鲜的新途径提供了理论依据。     

水溶性壳聚糖涂膜处理对采后绿芦笋贮藏品质的影响

研究了0.50%的水溶性壳聚糖(WSC)和羧甲基壳聚糖(CMC)分别对在2℃贮藏条件下采后绿芦笋的涂膜保鲜。通过感官品质、失重率、抗坏血酸含量、叶绿素含量、丙二醛(MDA)含量、总酚含量、多酚氧化酶(PPO)等生理生化指标的测定,以未经处理的绿芦笋为对照。结果表明:经0.50%的CMC和WSC进行涂膜处理,均可有效地降低芦笋的失重率,维持其硬度,延缓其抗坏血酸和叶绿素营养物质的消耗。而且CMC处理可以明显抑制绿芦笋总酚含量的下降及其PPO、POD和SOD活性的变化,其感官品质也明显优于对照组,使绿芦笋的贮藏时间延长至35 d。     

冰温贮藏后不同出库方式对绿芦笋品质的影响

研究了绿芦笋经冰温贮藏后不同出库方式对其品质的影响。实验以冠军品种绿芦笋为试材,经冰温贮藏(-0.2～-0.5℃)15d后,采用四种升温方式,研究不同出库方式对冰温贮藏后的绿芦笋品质的影响。结果表明:缓慢升温的出库方式可以有效地延长绿芦笋的货架期,其中G-2处理效果最为明显。方式G-2可使绿芦笋保持较好的感官品质、可溶性固形物含量和硬度,并有效地降低了绿芦笋呼吸强度、电导率和MDA含量,但G-2对绿芦笋VC含量和PAL活性的影响不大。     

芦笋中维生素C含量测定及变化规律

维生素C是评价植物营养品质的重要指标,试验采用2,6-二氯靛酚滴定法测定芦笋中维生素C含量,探讨不同品种(冠军、硕丰和井岗红)、部位(上段、中段和下段)以及贮藏条件(2个温度梯度和8个时间梯度)对芦笋中维生素C含量的影响。结果表明,在3个芦笋品种中以冠军维生素C含量最高,高达42.07 mg/100 g,且主要集中在上段部分,高达55.90 mg/100 g;维生素C对贮藏时间和温度非常敏感,延长贮藏时间会造成芦笋中维生素C大量损失。相对而言,低温贮藏对芦笋维生素C含量的保持率高于室温贮藏。     

臭氧水处理对绿芦笋贮藏品质的影响

研究了采用0.3 mg/L臭氧水处理的绿芦笋在8℃冷藏期间叶绿素、抗坏血酸、总酸度、水分含量和感官质量的变化。结果表明:处理后绿芦笋中叶绿素、抗坏血酸含量的下降速度低于对照,失重率降低,感官品质明显优于对照组,处理15 min组可延长贮藏期限达到15 d左右,但臭氧水处理对芦笋中总酸度影响不明显。     

不同变温方式对绿芦笋贮藏品质的影响

研究了不同变温方式对绿芦笋贮藏品质及相关酶类活性的影响。实验以阿波罗品种绿芦笋为试材,通过3种不同的升温方式,研究了变温方式对绿芦笋货架品质的影响。实验结果表明:逐渐升温的方式可以有效地延长绿芦笋的货架期,其中A-3处理效果最为明显,该处理可以使绿芦笋保持较好的感官品质和更高的可溶性固形物含量(TSS)。货架期为8d,A-3感官评分为17分,TSS为3.91%。而A-1感官评分为10分,TSS为3.42%;且A-3处理绿芦笋的硬度变化较小;同时,A-3能减缓绿芦笋电导率的上升,货架期为8d,其电导率为18.27%,而A-1处理为其1.2倍;A-3处理绿芦笋的PPO、POD和CAT活性总体高于其余两种处理和对照。     

芦笋保鲜技术研究及脂氧合酶抑制剂的保鲜应用初探

在冷藏加湿的基础上,通过对于芦笋贮藏过程中的失重率、叶绿素的含量,以及芦笋的木质化、散尖程度等感官指标的测定,比较了不同的处理方式对于芦笋的保鲜效果。在保持环境气体组成O210%、5%CO2的基础上,采用脱除乙烯和脂氧合酶抑制剂处理,可以有效保持芦笋的品质,延长货架期。     

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