不同种植密度对夏玉米胚乳细胞淀粉粒分布及形态的影响

以郑单 958为材料,通过不同种植密度,利用激光衍射粒度分析仪、扫描电镜及透射电镜, 分析不同种植密度夏玉米胚乳籽粒淀粉粒粒度分布特征。结果表明, 不同种植密度玉米籽粒淀粉粒的粒径下限一致 (0.38 μm),上限D1 > D2 > D3;体积、表面积及数目均值：D2 > D3 > D1。从淀粉粒的扫描图可以看出不同处理淀粉粒形态及胚乳细胞内其他内含物含量均有差异。从淀粉粒的透射图可以看出,各处理间淀粉粒的发育、外形、排列以及其他质体的数量都存在较大差异;密度可以调节玉米胚乳淀粉粒的分布及形态。     

不同活力种子对玉米产量与淀粉品质的影响

以玉米杂交种安科985和隆平206为材料，分析不同种子活力水平(相对发芽率100%、80%和60%)间玉米籽粒产量、淀粉粒度分布和黏度特性的差异。随着种子活力的降低，2个玉米品种穗长、百粒重、穗粒重、产量都呈降低的变化趋势，玉米胚乳大型淀粉粒组体积分布与数量分布的百分比显著减小(P<0.05),而淀粉粒表面积百分比显著增大(P<0.05),可见低活力种子不利于玉米胚乳淀粉粒个体体积增大。活力对籽粒淀粉含量的影响最大，蛋白质含量次之，脂肪含量相对较小。大型淀粉粒组(直径>16μm)的表面积分布百分比与淀粉稀懈值和峰值黏度呈显著负相关(P<0.05)。低活力种子，通过影响胚乳淀粉粒度分布，即减小大型淀粉粒比例，从而降低了玉米淀粉最终黏度、峰值黏度等糊化参数。     

玉米含油量及脂肪酸的分析

以郑单958、浚单20、中科11和先玉335四种玉米为材料,采用索氏抽提法提取玉米油。郑单958含油量最高,为6.6%;先玉335含油量最低,为1.5%。对四种玉米油和玉米毛油的理化性质进行测定。利用气相色谱分析玉米油的脂肪酸组成及含量,结果显示:郑单958、浚单20、中科11和先玉335的亚油酸含量分别为48.56%、50.10%、50.78%和55.33%。     

种植密度对沿淮玉米籽粒淀粉粒度分布与糊化特性的影响

分析不同种植密度对沿淮玉米籽粒中淀粉粒度分布与糊化特性的影响。以豫单132、京科968等13个玉米杂交品种为材料,设置56 250 株/hm2、67 500 株/hm2、77 250 株/hm2等3个种植密度,分析不同种植密度对玉米籽粒品质、淀粉粒度分布与糊化特性的影响。结果表明,在种植密度56 250~77 250 株/hm2范围内,随着种植密度的增加,玉米籽粒的蛋白质和脂肪含量呈递减趋势,淀粉含量呈递增趋势,即淀粉/蛋白质比率增加。玉米籽粒大型淀粉粒体积和表面积百分比显著增加,小型淀粉粒却显著降低。增加种植密度后玉米淀粉的峰值黏度、低谷黏度、最终黏度和稀懈值等黏度参数均呈显著升高。相关分析表明,玉米籽粒峰值黏度等黏度参数与小、大型淀粉粒体积百分比呈正相关,与中型淀粉粒体积百分比呈显著或极显著负相关。说明种植密度影响玉米籽粒淀粉粒度分布、淀粉黏度参数和组分含量。     

玉米霉变与其图像颜色特征参数之间的相关性研究

通过模拟玉米霉变过程,定时测定了玉米霉变期间的带菌量;同时利用扫描仪器对霉变玉米的图像进行采集,提取颜色特征参数,分析并探讨了霉变玉米的颜色特征与带菌量之间的相关性。结果显示,两种玉米在霉变过程中,随着储藏时间的延长,其颜色特征参数R、G、B、I值均呈减小趋势,并与霉变玉米的带菌量呈现负相关,郑单958带菌量与其特征参数G值相关性较高,达到-0.928 1,说明用G值表示郑单958的带菌量准确性较高;先玉335带菌量与其特征参数R值相关性较高,达到-0.939 0,说明用R值表示先玉335的带菌量准确性较高。试验结果表明,采用图像处理技术以图像颜色特征参数值来表示玉米的带菌量及霉变程度是可行的。     

新采收玉米籽粒中水分状态对淀粉热特性的影响

以2 种中国东北地区玉米郑单958（Zd958）和先玉335（Xy335）为研究对象,采用低场强核磁共振技术（low field nuclear magnetic resonance,LF-NMR）和差示扫描量热技术分析新玉米采后60?d内籽粒水分迁移和分布变化,及其对淀粉热特性影响。结果表明,东北新采收玉米采后水分T2弛豫时间和水分分布呈显著变化（P＜0.05）,2?种玉米淀粉凝胶焓值在40?d达到最高分别为18.54?J/g和15.06?J/g,结合水弛豫时间T21与籽粒水分含量呈极显著相关（P＜0.01）,结合水相对面积A21与籽粒水分含量呈极显著负相关（P＜0.01）,A21与凝胶吸热焓值（?H）呈显著相关（P＜0.05）,表明水分迁移和分布是影响淀粉分子晶体结构变化原因之一,利用LF-NMR技术可以有效分析采后籽粒内部水分动态变化,及其对淀粉功能特性影响。     

小麦胚乳A、B型淀粉粒的形成与生长特征及氮素调节

为研究小麦胚乳淀粉粒形成与生长特征,以优质小麦品种藁城8901为材料,在缺氮(对照)和施氮条件下,对籽粒发育过程中淀粉粒的产生、体积与数目分布及粒径变化进行比较。结果表明,花后4 d,小麦胚乳已出现A型淀粉粒,其中施氮处理粒径显著高于对照,说明氮素有利于早期淀粉粒的产生。花后10 d,又产生了一个新的小淀粉粒群体,即B型淀粉粒。花后10~12 d,施氮处理的粒径显著低于对照,可能是这个阶段施氮能促进小麦产生了更多的小(B型)淀粉粒,说明这个时期淀粉粒的生长以数目增长为主。花后14~17d,施氮处理淀粉粒粒径显著高于对照,说明这个时期淀粉粒生长以个体体积增大为主。花后24 d,0.8μm淀粉粒数目急剧增加,表明此期又产生了一个小淀粉粒群体。花后28 d,施氮处理0.8μm淀粉粒数目仍不断增加,表明施氮能促进灌浆后期籽粒产生更多的小淀粉粒。通过透射电镜观察发现,小淀粉粒是由大淀粉粒分裂而来的,单个存在。小麦胚乳A型淀粉粒形成和发育时期基本在花后14 d之前,而B型淀粉粒在成熟前,其体积和数目一直在增加。施氮有利于胚乳A、B型淀粉粒个体的增大和数目的增多。     

追氮对夏玉米淀粉含量及其糊化特性的影响

以郑单958为材料,研究玉米随追氮量增加玉米籽粒淀粉含量、淀粉相关酶活性及其淀粉糊化特性的影响,研究结果表明玉米籽粒淀粉及直链淀粉含量随追氮量的增加先升高后略有下降;腺苷二磷酸葡萄糖焦磷酸化酶(ADPG-PPase)、尿苷二磷酸葡萄糖焦磷酸化酶(UDPG-PPase)及束缚态淀粉合成酶(GBSS)的活性随追氮量的增加先升高后降低。可溶性淀粉合成酶(SSS)的活性随追氮量的增加先降低后升高;随追氮量的增加淀粉的峰值黏度、低谷黏度、最终黏度及崩解值先升高后降低,峰值时间以及糊化温度先降低后升高。     

玉米角质和粉质胚乳淀粉粒粒径、糊化特性及凝胶质构特性的研究

以莱农14、青农105、连胜15、隆平206和先玉335玉米为材料,人工分离角质和粉质胚乳,通过显微镜观察淀粉粒粒径,采用快速黏度测定仪(RVA)和物性测试仪(TPA)分析糊化特性和质构特性,比较玉米角质和粉质胚乳淀粉粒粒径、糊化特性和质构特性的差异。结果表明,角质胚乳淀粉粒平均粒径显著大于粉质胚乳;角质胚乳的峰值黏度、崩解值和凝胶回复性显著低于粉质胚乳,峰值时间和糊化温度显著高于粉质胚乳,而凝胶的硬度、弹性、凝聚性、胶着性和咀嚼性除了与胚乳质地有关外,也受品种的影响。在玉米实际加工利用时,可以根据需要选择不同类型的胚乳,以实现玉米胚乳的合理有效运用。     

储藏时间对玉米原粮中脂肪酸组成的影响

以2013年收获的"源玉3"和"先玉335"玉米原粮为试验对象,测定了样品中脂肪含量、脂肪酸组成及脂肪酸值随储藏时间的变化。并对完整籽粒和胚芽中的脂肪酸含量进行了比较分析。结果表明,在储藏270 d时间中,脂肪含量分别下降14.25%和12.19%。棕榈酸和硬脂酸含量呈先上升后下降趋势。油酸、亚油酸和亚麻酸含量呈下降趋势。5种脂肪酸含量在胚芽中所占比例略高于在完整籽粒中所占的百分比,但是脂肪酸含量变化规律保持一致,无显著差异。在本试验模拟粮仓储藏条件下,应用玉米胚芽提取玉米油的玉米原粮的适宜储藏期不宜超过210 d,但并不影响玉米原粮的宜存品质。     

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