粮食储藏生理性变质研究进展

粮食是人类赖以生存的物质基础,粮食储藏变质对农业生产及食品加工影响巨大。粮食生理劣变是一个复杂、渐进的物理、化学与生物学过程,与其籽粒的生理活动密切相关。研究表明,粮食籽粒酶活性降低,呼吸作用下降,生命力减弱等是其生理变质的外在表现,储粮生理活动是引发其生理劣变的本质要素。深入了解粮食籽粒在储藏过程中生理活动及其变化规律对揭示储藏生理变质机理具有重要意义。本文主要介绍了粮食籽粒储藏衰老过程中种胚微观结构、营养物质转化、线粒体呼吸作用、细胞抗氧化系统、遗传物质变异等的研究现状,并对粮食储藏保鲜原理进行讨论,以期为提出延缓和预测粮食储藏劣变的方法提供参考。     

小麦胚理化特性及其稳定化技术研究进展

叙述了小麦胚的营养价值和各种营养成分的生理保健功能,对小麦胚稳定化技术进行了研究分析：化学稳定法操作简单,抑酶活性高,稳定性好,但费用高;物理稳定法,从最初的低温储藏法到热处理法,再从挤压法到辐射法,逐渐趋于完善.     

不同储藏温度下小麦的品质劣变

小麦是我国的主要储备粮,小麦陈化是粮食储存中一个不可避免的问题,通过测定不同温度的储藏条件下,小麦的脂肪酸值和发芽率随着储藏时间延长的变化情况,探讨小麦品质劣变的变化规律,研究结果表明,储藏时间越长,储藏温度越高,小麦的脂肪酸值越大,发芽率越低,小麦的品质下降越快。     

糯性糙米气调储藏脂质变化的研究

实验研究三种储藏温度（15 ℃、25 ℃,35 ℃）和不同气调储藏（CO2、N2、真空）以及常规储藏方式条件下糯性糙米在不同储藏时间脂类物质的变化,发现储藏温度对糯性糙米脂肪酶活性、过氧化氢酶活性、脂肪含量、脂肪酸值、丙二醛和羰基值变化影响显著,同温度下气调组较常规组储藏对糯性糙米的储藏品质有较好的保护作用。研究表明,低温（15 ℃）条件下真空储藏可以减缓糯性糙米品质劣变。     

小麦储藏品质评价指标研究进展

小麦在储藏过程中会发生一系列的物理、化学、生理以及食用品质的变化。综述小麦储藏主要品质评价指标如发芽率、过氧化氢酶活性、脂肪酸值等,及其与储藏条件、储藏时间的关系,旨在为小麦的科学储藏研究提供参考。     

高温、高湿条件下模拟仓储小麦品质与微生物群落结构的变化

研究小麦从入库储藏到发现菌丝体过程中,其品质和微生物群落结构的变化趋势。以天津市实仓储藏的硬质白小麦籽粒为研究对象,以三角瓶为储藏容器,分别在30 ℃、60%RH,40 ℃、80%RH条件下对小麦进行模拟仓储,储藏时间为0~120 d。通过监测小麦籽粒的水分、色差、蛋白质、脂肪、淀粉、脂肪酸等品质指标变化,以及霉菌总数、高通量测序结果评估模拟粮库中小麦在不同储藏阶段的品质与真菌群落结构变化。结果表明,在30 ℃、60%RH条件下,储藏120 d内,小麦品质呈缓慢下降趋势,80~120 d曲霉属相对丰度迅速增加。在40 ℃、80%RH条件下,小麦品质劣变更快,在60 d时曲霉属相对丰度达100%,小麦产生可见菌丝体。研究表明随着储藏温度与相对湿度的升高,小麦品质变化速度明显加快,菌丝体产生速度加快。     

小麦储藏期间霉菌早期活动的快速监测*

将小麦置于不同温、湿度组合条件下进行模拟储藏,利用快速测定微生物活性值(基于过氧化氢酶活性)的方法监测小麦中霉菌的早期活动状态。结果表明,小麦储藏在70%~79%相对湿度条件下49 d,各试验组微生物活性检测的最大值为306 u;当储藏的相对湿度超过80%时,28℃试验组小麦储藏14 d后的微生物活性检测值即大于500 u。分析微生物活性值与小麦品质的关系表明,当检测值达到400 u时,检验发现小麦的品质有轻微劣变迹象。进一步研究还发现,小麦在各种环境条件下储藏的微生物活性变化与储藏时间有较好的线性关系,其线性相关性系数均达0.9或更高。因此,利用监测微生物活性值变化的方法可以对小麦储藏期间霉菌活动危害做出早期预警。     

稻谷储藏中细胞膜透性、膜脂过氧化及体内抗氧化酶活性变化

对国内不同储藏区域、储藏时间的120个商品稻谷样品的电导率、丙二醛(MDA)含量、过氧化氢酶(CAT)、过氧化物酶(POD)等生理生化指标进行测定,研究了稻谷在储藏过程中细胞膜透性、膜脂过氧化及体内抗氧化酶活性的变化规律,并讨论了上述变化产生的原因及其对储藏稻谷品质产生的影响.结果表明随着稻谷储藏时间的延长和陈化的加深,细胞膜透性和膜脂过氧化程度逐渐增大和加深,而其体内抗氧化酶(POD、CAT)活性则逐渐降低.由此可见,稻谷储藏过程中发生了氧化和过氧化作用,存在自由基损伤.     

LF-NMR和DSC技术在小麦仓储品质劣变分析中的应用

针对小麦仓储过程中出现的品质劣变问题,以北方实仓储藏的硬质白小麦为研究对象,通过测定仓储过程中小麦的色差、水分、脂肪、脂肪酸、淀粉含量等指标反映品质劣变程度;采用低场核磁共振成像技术（low-field nuclear magnetic resonance,LF-NMR）和差示扫描量热法（differential scanning calorimetry,DSC）可视化检测小麦仓储过程中水分传递和淀粉转变现象,寻找仓储过程中小麦水分迁移变化规律以及直链淀粉、支链淀粉的转化关系,探索小麦淀粉糊化反应。结果表明,小麦在仓储过程中色泽逐渐变暗,脂肪酸含量增加,水分、脂肪和淀粉总量减少,LF-NMR和DSC检测结果表明长期仓储小麦受环境因子影响会使其结合水的含量升高,自由水含量下降,糊化温度降低。     

小麦储存品质判定指标的研究

研究了小麦在3年常规储藏过程中,湿面筋含量、面筋吸水量和降落数值的变化规律及特点,研究结果表明：湿面筋含量和面筋吸水量与小麦储藏时间的相关性不佳,而降落数值的变化与小麦储存年限相关性最好,可以反映小麦储藏品质劣变和储藏年限,建议将降落数值作为小麦储存品质的参考判定指标。     

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