麦苗粉的微波杀菌

研究了微波功率、杀菌时间、物料量对麦苗粉杀菌效果的影响,在此基础上,以菌落总数和a*值为考察指标,采用正交试验进一步优化了麦苗粉微波杀菌的最佳条件,并与常规加热杀菌方法相比较;分析了麦苗粉杀菌前及经过最优工艺微波杀菌后的品质变化.结果表明,微波功率、杀菌时间对杀菌效果有重要影响,试验所得的麦苗粉最佳微波杀菌工艺为:微波功率510 W,时间120 s,物料用量12 g.与常规加热处理相比,麦苗粉采用微波杀菌不仅能达到较好的杀菌效果,而且品质保持良好.微波杀菌后麦苗粉的外观、色泽变化小;水分、灰分、总糖等理化指标基本不发生变化;叶绿素、维生素C等营养成分损失少.     

红枣汁微波杀菌工艺的确定与优化

以干红枣为原料,经清洗、破碎、浸提、澄清后,采用微波对红枣汁进行杀菌,利用正交试验研究微波功率、杀菌时间、物料量对杀菌效果的影响,并分析品质变化。结果表明,在微波功率900W、杀菌时间90s、样品量200mL时,杀菌效果较好,红枣汁品质较优。     

辣椒粉微波杀菌工艺的研究

辣椒粉可采用高温杀菌、辐照杀菌和微波杀菌等多种杀菌方式进行灭菌.本实验采用微波杀菌,在杀菌时间、微波炉功率、物料覆盖厚度不同条件下,分别以其中的一个条件为变量其他条件保持不变做单因素实验,以确定一个条件时辣椒粉杀菌的影响,找出最佳工艺条件.然后在单因素实验的基础上对辣椒粉进行正交实验,得到最佳实验工艺条件为:杀菌时间120 s、微波炉功率510 W、物料覆盖厚度15 mm.与常规加热处理相比,辣椒粉采用微波杀菌不仅能达到较好的杀菌效果,而且品质保持良好.     

豆酱微波杀菌工艺

以微波功率、辐照时间和装填量为工艺参数,以菌落总数、大肠菌群为检测指标,研究了豆酱的微波杀菌工艺条件,并与传统巴氏杀菌工艺进行比较,分析了杀菌前后豆酱感官品质和色差值的变化。结果表明:微波功率、杀菌时间与装填量对杀菌效果均有明显影响,豆酱微波杀菌最佳工艺参数为:3 400 W,120 s,100 g/袋。菌落总数减少99.9%,大肠菌群数<3.0 MPN/g,产品符合国家标准。与巴氏杀菌工艺相比,豆酱感官品质尤其是色泽变化更小。     

脉冲电场联合微波杀菌技术对干豆腐品质的影响及工艺优化

研究了脉冲电场联合微波杀菌对干豆腐品质的影响。结果表明,脉冲电场处理能起到杀菌的作用,同时达到钝化脂肪氧化酶的目的,且微波杀菌效果显著,制得的干豆腐产品豆腥味低,品质好,保质期长。在单因素试验基础上,通过响应曲面分析法对脉冲电场联合微波杀菌工艺进行优化,确定最优工艺条件为:脉冲强度33.95 k V/cm,脉冲处理时间432μs,微波功率601 W,微波时间24.6 s。     

水分调节对原料米糠微波稳定化的增效作用

食品物料中大都有水分存在,而水分子作为极性分子在微波场中有着极强的响应,本研究从优化微波稳定米糠工艺的角度出发,以米糠脂肪酶残余活力和酸价为主要指标值,着重考察米糠水分含量对微波稳定米糠效果的影响。研究发现,提高米糠水分含量对微波有明显的增效作用,通过单因素和正交试验得出微波稳定米糠影响因素大小依次为:米糠含水率>微波功率>微波处理时间;微波稳定优化水平组合为米糠含水率23%、微波功率800 W、微波处理时间105 s,该优化条件下米糠脂肪酶残余活力为20.24%,显示出高抑酶率且对米糠无热损伤。同时,以原始米糠为对照,将按上述最优条件处理的米糠和仅以功率800 W、时间105 s处理的米糠进行储存对比实验,定期测定米糠酸价以验证协同水分调节的最优微波稳定方案的稳定效果,实验证明,水分调节和微波协同作用处理后的米糠储存时间最长,分别为原始米糠储存时间的3.4倍和仅微波处理米糠的1.5倍,证实基于水分调节的微波处理对米糠稳定有显著效果。     

微波杀菌处理对番木瓜果浆品质的影响

主要研究番木瓜果浆微波杀菌中不同功率及不同处理时间的杀菌效果及其对产品主要品质的影响。结果表明:随着微波处理强度的加大菌落总数显著减少,550 W/60 s时即可达到商业无菌;经微波处理其可溶性固形物含量、还原糖含量、p H、ΔE值、总酚含量增加,总酸含量降低,试验范围内处理强度增大影响增大。当微波功率和处理时间控制在适当范围内时,番木瓜果浆中Vc和总黄酮含量变化不大,但当微波功率过大和处理时间过长时,下降速度加快。微波杀菌处理的番木瓜果浆部分抗氧化成分有所损失,但仍能保持番木瓜果浆的较强抗氧化性。     

微波在软包装竹笋杀菌保鲜上的应用研究

通过比较微波杀菌和常规杀菌对软包装竹笋的品质及营养成分损失的影响,确定软包装竹笋微波杀菌最佳条件。微波杀菌最佳条件是功率750W,时间180s。在此条件下杀菌,软包装竹笋质脆,色泽较白且蛋白质损失率仅为0.42%。从而推断微波杀菌效果优于常规杀菌。     

粉状食品微波杀菌工艺研究

以鹰嘴豆营养粉为原料,研究微波对粉状食品的杀菌效果。以细菌总数为指标,对营养粉微波杀菌工艺及效果进行研究。结果表明,营养粉杀菌的最佳工艺参数为:微波功率425W、杀菌时间120s、物料覆盖厚度15mm。     

鲜奶超声波除菌条件的优化

研究了经不同功率、时间、温度的超声波处理后鲜乳的杀菌效果,并研究了处理后牛乳的保藏期.结果表明:经600W,180s,60℃超声波处理的鲜乳,杀菌率达93%,并且对乳的营养成分无破坏作用,而且在4℃条件下保藏期迭8d左右仍具有较好的品质.     

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.     

Detection of adulteration of locust bean gum with guar gum by capillary electrophoresis and polarized light microscopy

Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH₃CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH₂PO₄-20.6 mM Na₂B₄O₇ buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.     

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%.