基于TMS320F28377S的双位置解算系统及其应用

为提高传动系统位置检测的精度和安全性以及减小系统首末端的位置偏差,提出了绝对式光电编码器和旋转变压器的双位置解算方案。基于高速芯片TMS320F28377S设计了绝对式光电编码器和DSP的通信电路,运用SCI模块与光电编码器通信;设计了旋转变压器与DSP的接口电路,对旋转变压器的输出信号进行160倍过采样并相敏整流;分别在传动系统首端和末端安装绝对式光电编码器和旋转变压器,位置解算结果相互验证,确保传动系统位置解算的正确性和安全性。实验表明该方案能快速准确地实现位置的检测,提高传动系统的性能。     

微流控芯片中亚硝酸盐的图像分析方法研究

为快速检测亚硝酸盐含量,提出一种基于图像分析技术的微流控芯片中亚硝酸盐快速检测方法,微流控芯片中设计两级反应池分别进行亚硝酸盐的初级反应和显色反应,采集显色反应后的图像并进行图像处理,提取显色反应图像,计算相对灰度值表征亚硝酸盐浓度。结果表明,亚硝酸盐溶液在0.5~10 mg/L浓度范围区间,所测显色溶液的相对灰度值与亚硝酸盐浓度呈线性关系,决定系数是0.9927,检出限为0.8 mg/L,检测时间小于10 min;对自来水和腊肉中的亚硝酸盐进行了测定,加标回收率在94.1%~108.0%之间。该方法拓展了微流控芯片中溶液浓度检测方法,具有简便、快速、准确的显著特点。     

腌制食品中亚硝酸盐的电化学检测

目的:制备基于磷钨杂多酸盐(Na3PW12O40)的多层膜电化学传感器,实现其对腌制食品中亚硝酸盐含量的快速检测.方法:用层接层法(Layer-by-Layer)将Na3PW12O40和PAH交替沉积于以(PEI/PSS/PAH)为底层的ITO电极上,制得多层膜亚硝酸盐传感器,分析该传感器的电化学性质,并利用其在溶液中对亚硝酸根的安培传感,测定腌制食品中亚硝酸盐含量.结果:制备的传感器在亚硝酸盐浓度1.67×10-8～3.23×10-6mol/L范围呈现良好的线性关系,I(μA)=0.125+0.630c(μmol/L),R=0.9992(n=10),响应电流达到95%时所需时间小于3s.结论:用电化学方法检测操作简便,灵敏度高,检出限低,结果准确,可用于腌制食品中亚硝酸盐含量的检测.     

基于酶联免疫法检测盐酸克伦特罗的微流控系统

基于微流控技术和酶联免疫法的原理建立动物性食品中盐酸克伦特罗残留的检测技术,确保食品安全。设计制作的微流控芯片结合搭建的微流控酶联免疫实验平台,可以实现对动物性食品中盐酸克伦特罗的现场、简便、快速的免疫反应和检测。结果表明:通过在芯片上包被盐酸克伦特罗抗原,由实验平台自动完成进样、清洗过程,30 min内即可实现对盐酸克伦特罗的快速检测。标准品检测范围为(0.10~8.10)ng/m L,加标回收率在95.5%~107.3%之间。使用微流控盐酸克伦特罗残留检测芯片系统,具有快速、自动化程度高、灵敏度高、成本低、方法学性能良好等优势,特别适用于非专业人士进行盐酸克伦特罗残留的现场、快速检测。     

微流控纸芯片在食品安全快速检测中的应用

微流控纸芯片,又称纸芯片,是用纸张代替了传统的微流控基底材料并将生化反应微缩于几平方厘米大小的纸上,构成的微型实验室分析系统。由于其低成本、便携性、热稳定性等优势,在质量控制与快速检测领域展现出了独特的创新和潜力。本文综述了纸芯片近几年在食品质量安全快速检测方面的研究进展,主要介绍了传统二维纸芯片制备过程中选择的纸质基材、微流控芯片亲水/疏水材料与技术和表面改性,深入三维结构纸芯片的流体通道构造,通道微阀、折叠等流体控制方式;重点介绍了2016—2022年纸芯片在食品质量安全快速检测方面（农兽药残留检测、致病菌检测、农药残留检测和食品掺假鉴别）的最新应用进展,并讨论其在未来的发展趋势与目前所面临的挑战,以期为纸芯片在食品安全检测领域的发展提供有效参考。     

基于TMS320F28335的伺服系统数字化速度环设计

针对传统伺服系统模拟速度环难以实现高精度高性能的控制要求,文章设计并阐述了数字化速度环系统的结构原理与硬件实现。系统采用LTC1821芯片为数模转换(D/A)器件,以DSP芯片TMS320F28335为核心控制器,选用光纤陀螺仪作为速度反馈装置,搭建高精度速度环伺服跟踪平台。仿真实验证明,通过DSP软件设计与调试,运用增量式比例积分(PI)调节算法,该系统具有响应速度快,低超调和闭环精度高等优点。     

超级细菌NDM-1基因高通量微球悬浮芯片检测方法的建立

本研究以建立微球体悬浮芯片检测方法为目的,选择三种超级细菌NDM-1基因(metallo-beta-lactamase 1 gene)为目的基因,设计并合成标记特异性探针,与荧光编码微球偶联后与细菌NDM-1基因的PCR产物杂交反应,用微球悬浮芯片检测仪检测荧光信号,建立可快速检测该种基因的微球体悬浮芯片检测方法。特异性和灵敏度检测结果表明:该方法对NDM-1基因检测具有特异性,最低检测限可达10fg/μL,灵敏度高于普通PCR技术,提示微球体悬浮芯片是一种针对NDM-1的快速、灵敏、便捷的新型核酸检测技术。     

用于五种动物源性成分快速检测的离心式微流控芯片系统研制

基于离心力驱动原理与重组酶介导扩增技术,研制了一套用于牛、羊、猪、鸭、鸡源性成分快速检测的离心式微流控芯片系统。设计制作了扇形微流控芯片和配套使用的密封盖片、芯片托盘装置,同时搭建了集恒温控制平台、流体控制模块和光电检测模块于一体的便携式微流控速测仪,可实现动物源性成分的核酸恒温扩增及荧光检测。每次可同时检测5个样本,每个样本可同时检测5种指标。考察结果显示,离心式微流控芯片系统可检出牛、羊、猪、鸭、鸡源性成分的最小质量分数分别为1%、1%、0.1%、0.1%、1%,能够在30 min内实现半定量检测,具有快速、自动、高通量的特点,显示了离心式微流控芯片可快速检测肉制品掺伪的潜力。     

应用可视芯片技术检测食品中常见致病菌的方法研究

利用特异性引物进行PCR扩增,并利用固定于可视芯片的特异探针与扩增产物进行杂交反应加以鉴定。利用可视芯片技术可以准确的检出沙门氏菌属和金黄色葡萄球、小肠结核肠炎耶尔森氏菌、单核细胞增生李斯特氏菌3种食品中常见致病菌,检测灵敏度可达8.5×101cfu/mL。利用可视芯片准确灵敏使用便捷的优点,建立了食品中常见致病菌鉴定方法,为食源性致病菌检测提供了一项快速有效的方法。     

基于嵌入式系统的气溶胶热发生器的关键技术研究

文章是基于嵌入式系统对气溶胶热发生器的关键技术——温控系统的研究,以高速MCU为主控芯片,搭建温度控制系统闭环回路,采用双波段温度控制技术,可快速达到温度控制目标并稳定,实现开机3分钟即可工作,基于该温度控制系统,顺利开发了基于蒸发冷凝原理的气溶胶热发生器,经过测试,气溶胶热发生器在165秒达到所需温度并最终保持在400℃,实现温度的快速高精度控制。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

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.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

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.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.