沙门氏菌在几种香料上存活特性的研究

以红辣椒、灯笼椒和黑胡椒为实验材料,采用人工回接沙门氏菌的方法,研究沙门氏菌在不同温度和水分活度条件下,在香料中的存活特性。结果表明:沙门氏菌在香料中的存活受温度和水分活度的影响;沙门氏菌在黑胡椒中短时间内会迅速增长,在2种不同辣椒中48 h之内变化不大,但是经过5 d以后会逐渐死亡,而且水分活度越大,存活的时间越长,温度越高死亡得越快。     

低水分活度食品的微生物安全研究进展

由于低水分活度可抑制微生物的生长繁殖,因此低水分活度食品一直被认为是微生物安全的。然而近几年发生的多起由低水分活度食品中的病原菌引发的安全事件表明：低水分活度食品存在较大食品安全隐患。虽然微生物在低水分环境中难以生长、繁殖,但可以在不同的贮藏条件下存活很长一段时间,当含有微生物的低水分活度配料,被添加到高水分活度的食品中时同样会引发微生物交叉污染的问题。目前,低水分活度食品的微生物污染已开始成为新的食品安全问题。本文总结近年来部分低水分活度食品微生物安全事件,着重阐述低水分活度食品中微生物的热失活规律、机制及其控制方法。     

金华火腿成熟过程中致病菌存活状况及理化指标变化的研究

研究了金华火腿成熟过程中理化指标的变化情况,结果表明:火腿在成熟过程中其水分含量、水分活度、pH值等不断降低,盐含量不断升高.对致病菌的研究表明:金黄色葡萄球菌、沙门氏菌等致病菌在火腿上不能生长.低水分活度是抑制它们存活及生长的主要因素.另外,低水分含量、高盐含量及乳酸菌和霉菌的生长对致病菌的存活也有一定的抑制作用.火腿成熟期间,菌落总数呈下降趋势.     

大型赛事中微生物致病菌项目样品的运输方案研究

为了及时并准确发现赛事期间餐饮环节的卫生情况及潜在危害,加强食品安全监管,依据“十四运会和残特奥会食品安全抽检工作方案”对常规微生物致病菌项目的样品采集、运输条件及时间进行模拟测试。结果表明,沙门氏菌、单核细胞增生李斯特氏菌在不同温度条件下的生长情况良好,而金黄色葡萄球菌在4 ℃条件下,菌落数量存在一定程度的衰减,但数量级并没有变化,而在-18 ℃条件下,菌落数量变化程度较4 ℃情况下有所减缓。     

低水分辣椒粉带菌状况及控制技术的研究

对48份低水分辣椒粉样品带菌状况进行取样分析,结果表明其带菌量在2.2×104～2.8×106CFU/g之间,平均带菌量为4.8×105CFU/g,球菌和芽孢杆菌为优势菌。对辣椒粉生产各环节进行取样分析,指出烘烤虽可以最终减少辣椒粉的带菌量,但不能达到完全灭菌的目的,样品中芽孢杆菌含量直接影响烘烤灭菌率。用臭氧分别对粉状和整形辣椒进行灭菌处理,结果表明臭氧处理厚度为1mm的辣椒粉1h灭菌率为5.0%,辣椒粉表层会发生褪色且有异味,臭氧处理5d可使整形辣椒的带菌量由1.5×106CFU/g减少到6.8×103CFU/g,再经烘烤、粉碎后其带菌量减少为1.2×102CFU/g,臭氧对不同带菌状况的辣椒均取得较好的灭菌效果。     

肠炎沙门菌的温度、pH值和水分活度主参数模型的构建

为探究不同环境条件对肠炎沙门菌的生长规律影响,以液体培养基为基质,采用Baranyi模型作为一级模型,主参数模型作为二级模型。建立肠炎沙门菌在不同温度（30～42?℃）、pH值（6.6～8.0）、水分活度（0.976～0.997）环境影响下的主参数模型,基于Gamma概念,研究3?种环境的独立影响。通过决定系数评价一级模型的拟合程度、数学检验值以及拓展检验评价二级模型的有效性。结果显示：Baranyi模型可以很好地拟合肠炎沙门菌的生长（R2＞0.900）。拟合得到的主参数模型参数值分别为：Tmax?44.51?℃、Topt?34.24?℃、pHmax?8.14、pHmin?6.09、pHopt?7.55、aw（min）0.957和aw（opt）0.997,实验范围内随机组验证主参数模型得到的均方误差为2.311×10－5、偏差因子为0.963和准确因子为1.267,均在可接受范围内。本实验构建的主参数模型能有效描述肠炎沙门菌的生长状况,为食品安全保证提供良好的理论依据,可用于减少由致病菌引发的食品安全风险。     

水油混相协同微波提取辣椒碱工艺优化及应用研究

目的：优化干辣椒中辣椒碱的提取工艺并探究其加工特性。方法：采用高压水油混相浸提技术预处理干辣椒,再协同微波辅助溶剂法提取辣椒碱,并应用于食品加工中。结果：水油混相预处理工艺条件为干辣椒粗粉加湿量20%、浸提温度150 ℃、搅拌机转速300 r/min;微波辅助提取工艺条件为预处理的辣椒粉在600 W微波功率下处理120 s,然后按料液比（m_辣椒粉∶V_乙醇）1∶20 （g/mL） 添加65%的乙醇,在30 ℃恒温水浴锅中浸提2.5 h,辣椒碱最佳提取量为4.12 g/kg干辣椒,初次提取率达82.4%,3次理论得率可达99.45%。结论：高压水油混相浸提技术预处理后的干辣椒辣椒碱提取率显著优于传统浸提工艺,且加工性能稳定。     

不同灭菌预处理方法对低水分调味料带菌状况的影响

对11种低水分调味料带菌状况进行了取样分析。结果表明,辣椒粉微生物污染最严重,48份样品平均带菌量为4.8×105个/g。应用不同的灭菌预处理对其进行带菌量控制的研究,结果表明,臭氧灭菌进行预处理后,辣椒经车间烘烤、粉碎后其带菌量能达标,而采用紫外、微波灭菌预处理后的辣椒带菌量仍超标。     

杨梅采后贮藏温度和包装方式对表面沙门氏菌的影响及预测模型构建

为比较不同温度、包装方式的杨梅表面沙门氏菌数量变化情况,建立细菌生长/衰亡模型,测定了4,16,25,33℃条件和普通塑料袋包装、保鲜膜包装方式的杨梅表面沙门氏菌生长/衰亡数据;选用Logistic模型为初级模型,拟合不同温度和不同包装方式的杨梅中沙门氏菌生长/衰亡曲线。结果显示,冷藏(4℃)可有效抑制甚至减少细菌数量;低温通风贮藏(16℃)可在一定时间内抑制细菌繁殖,贮藏时间小于30 h;夏季高温条件(33℃)下未见细菌增殖迟滞期,细菌繁殖速度快,风险值得关注。低温贮藏(4,16℃)时不同包装方式对细菌生长/衰亡无显著影响。33℃条件下保鲜膜能有效减缓细菌生长。根据模型评价参数adj-R~2、RMSE,A_f,B_f等对模型进行内部和外部验证,根据Logistic模型进行细菌数量预测。本研究结果可用于杨梅采后沙门氏菌污染控制,为微生物定量风险评估提供重要信息。     

沙门氏菌在鲜切蔬菜中生长行为及其预测模型构建

为揭示沙门氏菌在鲜食蔬菜或调味蔬菜中的生长情况,以蒜苗、香菜、西红柿、黄瓜和小葱为实验对象,点植接种两株沙门氏菌混合菌液(Salmonella enteritidis ATCC 13076和S.newport ATCC 6962),研究不同接种剂量下沙门氏菌在鲜切蔬菜中生长情况,考察不同温度下沙门氏菌在鲜切黄瓜中的动态生长情况,并构建生长模型。结果表明:4℃下,沙门氏菌在所试鲜切蔬菜中均不生长。28℃,高接种剂量下(2.0 log CFU/g和3.0 log CFU/g),沙门氏菌在各种蔬菜中的生长势(δ)在4.25~5.84 log CFU/g之间,表明其在各种蔬菜中生长良好(菌落数量7.0 log CFU/g)。1.0 log CFU/g接种剂量下,除了黄瓜外,沙门氏菌在其他蔬菜中生长良好(菌落数量约5.0 log CFU/g)。微量接种剂量0.1 log CFU/g,小葱和番茄中沙门氏菌长势尚好(δ0.5 log CFU/g),其他蔬菜中沙门氏菌不生长(δ0.5 log CFU/g)。采用Baranyi模型对实测数据进行拟合,结果显示:7、15、20和25℃下沙门氏菌在鲜切黄瓜中的最大比生长速率(μmax)分别为0.026、0.11、0.14和0.29 h-1;7℃和15℃时,迟滞时间分别为24.33 h和9.44 h,20℃和25℃时不经历迟滞期,直接进入对数生长期。采用次级模型Ratkowsky方程描述最大生长速率和储藏温度的关系,模型可靠性较好。所以,蔬菜品种、接种剂量和储藏温度影响沙门氏菌在鲜切蔬菜中的生长。     

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