麦胚稳定化处理方法的比较研究

研究了热风干燥、微波干燥、常压蒸汽和高压蒸汽处理麦胚对其加速储藏期间脂肪酶的钝化效果.在38℃下进行35d的加速储藏实验,进行跟踪检测,以酸值和过氧化值作为钝化脂肪酶的表征参数,对不同方法处理原料的优化结果(酸值和过氧化值)进行了比较.结果表明,脂肪酶的钝化效果:湿热蒸汽处理的效果优于微波干燥,明显好于热风干燥处理,酸值和过氧化值均上升缓慢,常压蒸汽处理20min即可达到预定效果.对常压蒸汽处理的麦胚原料进行超临界萃取并对得到的麦胚油进行了GC分析,与对照组原料相比,脂肪酸组成与含量均无明显变化.水蒸汽是良好的热载体和传热介质,蒸汽处理能够有效钝化脂肪酶的活力,提高小麦胚芽的贮藏稳定性.     

小麦胚芽稳定化技术比较研究

通过热风干燥、微波干燥、高压蒸汽处理和常压蒸汽处理对小麦胚芽进行预处理,并在35℃下进行30天贮藏实验,然后检测酸价、过氧化值等指标,评价不同处理对脂肪酶的钝化效果。结果表明:按照钝化效果由高到低分别为高压蒸汽处理常压蒸汽处理热风干燥处理微波干燥处理。其中高压蒸汽处理的最优条件为:压力0.01 MPa,处理时间30 min,在此条件处理后,可大幅延长小麦胚芽贮藏期间的各项品质。     

不同稳定化方法对麦胚储藏特性的影响研究

新鲜麦胚稳定性差,不耐储藏。采用不同的稳定化方法处理麦胚以提高其储藏稳定性及开发利用率。通过测定加速储藏期间各组麦胚的酸值及过氧化值的变化,可以得出不同稳定化方法处理麦胚的稳定化效果优劣顺序为:微波耦合壳聚糖覆膜法微波法湿热法干热法壳聚糖覆膜法对照组。     

微波协同无机盐处理麦胚的稳定效果研究

为探寻一种新型的小麦胚芽稳定方法,采用热风干燥、微波、热风+NaCl、微波+NaCl 4种稳定化方式处理麦胚,分析处理前、后麦胚水分含量、水分活度、脂肪酶活力、酸价、氧化稳定性和脂肪酸组成的变化。结果表明,4种稳定化处理均显著降低麦胚的水分含量与水分活度,有效抑制脂肪酶的活力,其中微波+NaCl处理的麦胚脂肪酶活力下降68.81%;酸价分析结果表明,微波+NaCl处理的麦胚,经加速贮藏,酸价变为原来的175%,而对照组变为原来的375%;麦胚油氧化稳定分析性结果显示,稳定化处理的麦胚氧化诱导时间缩短,稳定性下降,而微波+NaCl处理组的稳定性显著高于其它处理组(P0.05)。由此可见,微波+NaCl处理可作为一种有效的麦胚稳定化处理方法,有效抑制脂肪酶活力,延缓酸败,达到延长麦胚贮藏期的目的。     

小麦胚微波稳定化工艺参数初探

研究了微波功率、处理时间、小麦胚原料水分对小麦胚的脂肪酶活力及其储藏稳定性的影响。结果表明,微波处理可钝化小麦胚的脂肪酶,有利于小麦胚的储存;水分在微波稳定小麦胚过程中起着重要的作用,适当提高水分有助于小麦胚吸收微波能量,加快酶失活速率,提高小麦胚储藏稳定性。     

稳定化处理方式对麦胚的贮藏稳定性、抗氧化活性和总酚含量的影响

对比了挤压(EX)、红外(IR)、常压汽蒸(AS)、高压汽蒸(HPS)、紫外微波(UVM)、常压汽蒸耦合紫外微波(AU)6种稳定化处理方式对麦胚的贮藏稳定性、抗氧化活性和总酚含量的影响.结果表明:在30 d贮藏期内,未处理麦胚的脂肪酸值增长率为124％,稳定化处理麦胚的脂肪酸值增长率仅为8％～24％;AU稳定化处理效果最好;IR处理的麦胚DPPH、ABTS自由基清除能力都较强;EX处理使麦胚螯合铁离子能力显著增强;各稳定化处理方式对麦胚的总酚含量影响不大,仅EX处理使其总酚含量略微增加.因此,6种处理方式均能很好地稳定麦胚.     

不同处理技术对小麦胚芽钝酶效果及贮藏稳定性的影响

目的：采用3种不同处理技术对小麦胚芽进行稳定化处理,以获得最优的小麦胚芽钝化技术及处理条件。方法：选用微波、过热蒸汽、热风干燥3种技术对小麦胚芽进行酶钝化处理,比较其对小麦胚芽中脂肪酶、脂肪氧化酶的影响,随后选取其中较优处理条件进行菌落总数的测定和加速贮藏试验。结果：3种技术在最优处理条件下均能够有效地对小麦胚芽中的脂肪酶、脂肪氧化酶起到钝化作用,其中过热蒸汽技术灭活脂肪酶效果最佳,灭活率达到82.79%;微波技术灭活脂肪氧化酶效果最佳,灭活率为94.81%;过热蒸汽技术灭菌效果最佳,使菌落总数下降至2.20 lg（CFU/g）;贮藏稳定性方面,微波和过热蒸汽技术效果相近,显著优于热风干燥技术效果。结论：综合来看,过热蒸汽技术可作为小麦胚芽钝化处理的优选技术。     

小麦胚加工储藏稳定化研究

探讨了小麦胚加工储藏稳定化方法。麦胚经过用蒸汽蒸煮 30min、 90℃微波处理3min、添加 0 2 %麦胚量的抗氧化剂异抗坏血酸钠、采用真空包装等综合处理的方法可大大延长麦胚的储藏期。经加工配制的麦胚片固体饮料的储藏稳定性较好 ,储藏期 1年的过氧化值仅为 18 6meq/kg。     

热处理对米糠及米糠油特性的影响

用常压蒸煮、高压蒸煮和微波处理米糠,研究热处理方法对米糠及米糠油品质的影响。结果表明,三种热处理方式均能使米糠的水分下降,抑制过氧化物酶和脂肪酶活力,使储藏过程中脂肪酸值上升速度减慢。其中常压蒸煮米糠的过氧化物酶和脂肪酶活力下降最多;微波处理的米糠在储藏过程中脂肪降解最慢,过氧化物酶和脂肪酶活力有下降的趋势,提出的米糠油品质优于常压蒸煮和高压蒸煮。     

小麦胚加工储藏稳定化研究

探讨了小麦胚加工储藏稳定化方法。麦胚经过用蒸汽蒸煮30min、90℃微波处理3min、添加0．2％麦胚量的抗氧化剂异抗坏血酸钠、采用真空包装等综合处理的方法可大大延长麦胚的储藏期。经加工配制的麦胚片固体饮料的储藏稳定性较好，储藏期1年的过氧化值仅为18．6meq／kg。     

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