干制条件对杏果中糖含量变化的影响

以新疆赛买提杏为原料,研究热风干制和自然晒制过程中糖含量变化规律,包括果糖、葡萄糖、蔗糖、果胶和粗纤维等。结果表明,杏果实中葡萄糖含量大于果糖含量,干制过程中果糖、葡萄糖及还原糖含量降低,且热风干制温度越高,还原糖降解幅度越大。热风温度处理有利于杏果中蔗糖和可溶性总糖在干制初期的积累。随着干制温度升高,蔗糖与果糖、葡萄糖、还原糖的相关性由极显著负相关水平逐渐向正相关水平转化,说明热作用下蔗糖又降解成果糖和葡萄糖等还原糖类物质。干制过程中可溶性果胶含量增加,原果胶和粗纤维含量降低,说明在干制过程中杏果存在后熟软化的现象。因此,通过控制干制条件在一定范围内能够调控杏果中糖的组分和含量,改善杏干的品质。     

套袋对清见橘橙果实蔗糖代谢的影响

研究6 种果袋对清见橘橙果实可溶性糖含量及蔗糖代谢关键酶活性的影响。结果表明：不同果袋对清见橘橙果实可溶性糖含量的影响不同,单层果袋显著提高了果实的可溶性糖含量。果实成熟时,套白色单层无纺布袋的果实蔗糖含量最高,套黄色单层袋和白色单层袋的果实果糖含量均最高,套白色单层袋的果实葡萄糖含量最高。单层果袋提高了果实中性转化酶（NI）、蔗糖合酶（SS）和蔗糖磷酸合酶（SPS）的活性,以无纺布袋最为明显,而双层果袋对NI、SS、SPS活性的影响在多数测定点差异不显著。酸性转化酶（AI）活性随着果实的成熟而降低,套袋对AI活性的影响不显著。综上可知,单层果袋通过提高NI、SS、SPS的活性来提高糖含量,因此清见橘橙宜选择具有一定透光率且色泽浅的单层果袋。     

不同品种烤烟成熟期糖代谢酶活性及基因的表达分析

为了探究不同品种烤烟成熟期糖代谢的变化规律,明确烟叶品质形成的分子作用机理。以烤烟品种秦烟96、豫烟6号和K326为试验材料,测定分析了烤烟成熟期水溶性糖组分（葡萄糖、果糖、麦芽糖、蔗糖、还原糖和可溶性总糖）含量、糖代谢关键酶活性及基因表达的变化。结果表明,3个品种烤烟水溶性糖组份含量变化趋势基本一致,各水溶性糖（蔗糖除外）含量呈先升高后降低的变化趋势,烟叶成熟时其含量达到峰值;蔗糖含量呈双峰波动,烟叶成熟时蔗糖含量较低。烟叶打顶至适熟阶段,SPS和AI酶活性对烟叶中水溶性糖的积累贡献最大,NtINV对烟叶糖代谢起主要调控作用;当烟叶由适熟至过熟时,AI酶活性主要参与烟叶糖代谢活动,而SS和SPS则对蔗糖积累起重要作用,NtSS和NtSPS对烟叶糖代谢起主要调控作用。同一生态环境和栽培条件下,豫烟6号内含物质充实,具有较高的水溶性糖分含量,SPS和AI酶活性的差异可能是造成烟叶糖组分及含量不同的重要原因。     

保水剂吸附尿素对‘赤霞珠’葡萄果实糖积累及蔗糖代谢酶活性的影响

以田间栽培晚熟酿酒葡萄‘赤霞珠’为试材,设置5个处理,测定保水剂吸附尿素对葡萄糖组分含量及相关代谢酶活性的影响。结果表明,保水剂吸附尿素显著提高了果实成熟前期的总糖含量和果糖含量,而葡萄糖和蔗糖含量减少;但保水剂吸附尿素提高了成熟中期果实的葡萄糖含量,在果实成熟时各处理的糖组分没有显著性差异。相应地,对果实蔗糖代谢相关酶活性的测定表明,主导蔗糖分解方向的AI酶活性最高且果实成熟前期和中期均以保水剂吸附尿素的处理显著较高,而保水剂吸附尿素显著降低了蔗糖合成酶SS的活性且变化趋势与蔗糖含量相反。相关分析表明,各处理分解方向的AI、NI活性与葡萄糖、果糖、蔗糖含量均呈显著的负相关,而合成方向的两种酶与糖组分含量之间无显著相关性。     

高湿贮藏对青花菜黄化和糖代谢的影响

为探讨高湿贮藏对延缓青花菜黄化的作用及其与糖代谢的关系,将青花菜分别置于(4.0±0.5)℃的干雾控湿高湿冷库(相对湿度:95%～98%)和普通冷库中(相对湿度:70%～75%)贮存36d,每隔6 d取样测定相关品质指标。结果表明:高湿贮藏能显著延缓青花菜质量损失率和黄化指数的上升,抑制叶绿素酶和脱镁螯合酶的活性,保持较高的叶绿素a、叶绿素b和总叶绿素含量。同时与低湿贮藏相比,高湿贮藏能够增强蔗糖磷酸合酶的活性,降低蔗糖酸性转化酶、葡萄糖激酶和尿苷二磷酸葡萄糖焦磷酸化酶的活性,维持较高的蔗糖、果糖和葡萄糖含量。这些结果表明,高湿贮藏可通过调控糖代谢相关酶活性维持较高的可溶性糖含量,从而延缓青花菜的黄化。     

枣干制过程中可溶性糖含量变化的规律

针对新疆枣在自然干制过程中品质劣变的现象,研究采用自然干制和热风干制两种方式干制红枣,枣中果糖、葡萄糖和蔗糖等可溶性糖含量的变化规律.结果表明:在干制过程中果糖、葡萄糖与还原糖含量均呈上升趋势,蔗糖等非还原糖与可溶性总糖含量均呈下降趋势;各种糖含量发生显著变化的时期主要在干制初期,干制工艺对糖含量的变化影响较大;在干制过程中,非还原性糖大量降解,其中高温和低温长时干制时降解量大;果糖含量始终高于葡萄糖含量,且干制过程中二者的消耗量几乎一致.     

骏枣干制过程中几种营养物质的变化规律

采用自然干制、热风干制和真空冷冻干制3种方式干制新疆骏枣,研究骏枣在干制过程中的VC、总酸、总糖、蔗糖、果糖、葡萄糖、可溶性蛋白质含量的变化规律。结果表明:在干制过程中,VC和总酸含量呈下降趋势,VC在干制过程中损失率极大;总糖、果糖和葡萄糖含量均呈上升趋势,而蔗糖含量呈下降趋势;可溶性蛋白质含量呈先下降后上升的趋势。以上几种营养物质的保存过程中,真空冷冻干制保存率最高,热风干燥次之,自然干制最低。     

外源葡萄糖通过调控蔗糖代谢增强采后杏果实的抗冷性

为探究外源葡萄糖处理对杏果实采后抗冷性与糖代谢的影响，本实验以新疆‘赛买提’杏为原料，采用不同浓度葡萄糖进行减压渗透处理，晾干后，置于温度（0±1）℃的冷库中贮藏49 d，定期测定杏果实冷害发病率、冷害指数、品质及糖代谢相关指标。结果表明：200 mmol/L外源葡萄糖处理可有效抑制杏果实冷害发病率、冷害指数与细胞膜渗透率的上升与丙二醛（malondialdehyde,MDA）的积累，较好地维持杏果实硬度、色泽、可溶性固形物质量分数（soluble solids content,SSC）、可滴定酸（titratable acidity,TA）质量分数与抗坏血酸（ascorbic acid,ASA）含量。同时，与对照组相比，200 mmol/L外源葡萄糖处理提高了杏果实酸性转化酶（acid invertase,AI）、中性转化酶（neutral invertase,NI）、蔗糖磷酸合成酶（sucrose phosphate synthase,SPS）和蔗糖合成酶（sucrose synthase,SS）活力，显著促进了贮藏过程中葡萄糖及果糖的积累，但在贮藏中后期（21～49 d）降低了蔗...     

不同干制方法对金丝小枣中糖类物质的影响

本文分别采用热风干燥法、日晒法和微波干燥法对金丝小枣进行干制,研究以上三种方法对红枣中可溶性糖、果胶含量及果胶分子量分布的影响。结果表明:与新鲜枣果相比,所有干制处理均导致山梨醇和蔗糖含量显著降低(p0.05),其中微波和日晒处理枣果的蔗糖保留率比热风处理组高,但其果糖与葡萄糖含量低于热风处理组。干制处理导致枣果细胞壁、水溶性果胶和溶于Na_2CO_3型果胶含量显著下降(p0.05),而其螯合性果胶含量显著增加(p0.05)。干制导致枣果果胶分子量显现不同趋势的变化。水溶性果胶组分:热风70℃或日光晾晒处理均导致高分子端组分的减少,热风50℃处理其分子量分布最为集中;溶于Na_2CO_3型果胶组分:干制导致高分子端果胶组分的增加,低分子端组分则发生降解。     

采后黄冠梨果实糖代谢及相关酶活性变化规律

以黄冠梨为试材,研究采后梨果实糖代谢及相关酶活性的变化规律。果实采后即贮于温度0℃、相对湿度85%～95% 的冷库中,分别测定贮藏过程(0～240d)中果实中葡萄糖、蔗糖、总可溶性固形物(TSS)和可滴定酸(TA)的含量以及酸性转化酶(AI)、中性转化酶(NI)、蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)的活性。结果表明：在采后贮藏期间,黄冠梨果实中葡萄糖含量与AI、NI 活性均呈先升后降的趋势,且AI 活性出现明显高峰,而蔗糖含量与SS、SPS 活性均逐渐降低。TA 和TSS 含量是果实风味的重要指标,随着贮藏期的延长,TA 含量逐渐下降,而TSS 含量呈升- 降- 升的趋势。果实中蔗糖代谢参与酶的净合成活性与果实中蔗糖的积累密切相关,在采后贮藏期间其活性逐渐降低。     

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