液相色谱—串联三重四极杆复合线性离子阱质谱法测定水生蔬菜中45种抗生素

目的:建立超高效液相色谱—三重四极杆复合线性离子阱质谱法同时测定水生蔬菜中多种抗生素类化合物。方法:样品以含0.1%甲酸的乙腈溶液为溶剂,加入N-丙基乙二胺(PSA)、无水Na₂SO₄和C₁₈净化处理,质谱采用分时段多反应检测—信息关联—增强子离子(SMRM-IDA-EPI)扫描模式及谱库检索技术,通过对化合物保留时间、离子对及EPI谱库检索对比,外标法定量。结果:45种抗生素在1.0~100.0 μg/L质量浓度范围内线性关系良好(R²＞0.99),检出限为0.3~1.0 μg/kg,定量限为1.0~3.0 μg/kg,在3个浓度添加水平下,45种抗生素的回收率为60.4%~121.7%,相对标准偏差为0.9%~10.2%。结论:该方法快速简便、定性能力强,适用于水生蔬菜中45种抗生素类化合物的筛查确证和定量检测。     

基于改进鲸鱼算法和神经网络的食品机器人能耗轨迹规划

目的:针对食品工业机器人动力学参数未知的节能轨迹规划问题,提出一种基于鲸鱼算法和神经网络的点到点机器人关节能耗轨迹规划方案。方法:构建食品机器人移动机械臂点到点关节能耗模型,设计基于神经网络的相似动力学辨识,用改进的鲸鱼算法对权重和偏置参数进行离线优化;采用四次多项式插值法规划关节移动轨迹,将轨迹参数等效为鲸鱼编码,通过求解关节能耗目标优化函数,最终得到能耗最优的关节运动规划轨迹。结果:该方案适用于机器人动力学参数未知下的轨迹规划场景,得到的轨迹能耗比同类降低约9.01%。结论:基于鲸鱼算法和神经网络的轨迹规划能实现食品机器人能耗优化目标。     

低场核磁共振技术快速鉴别注水注胶肉的化学计量学研究

目的 利用化学计量学方法结合低场核磁共振对注水或注胶猪肉的快速鉴别进行研究。方法 首先利用低场核磁共振测定获得的17个变量进行提取主成分,并对获得的4个主成分进行判别研究模型。利用低场核磁共振技术的17个原始变量作为输入,原料肉与注水注胶肉的种类作为输出,采用不同建模参数,通过多次计算,建立了一个结构为17-6-3的三层MLP神经网络识别模型。结果 判别研究模型中对照组、注水组和注胶组交叉验证判别正确率分别为60/60、91/95、359/384,总的正确判别率达到94.6％;神经网络识别模型对检验集179个样本总的正确识别率达到97.8％。结论 利用低场核磁共振技术结合判别研究模型和神经网络识别模型可以有效分辨注水注胶肉,该方法具有简单、快速的优点,可以用于注水注胶肉的快速检测。     

核酸-免疫层析法快速检测肠道侵袭性大肠埃希氏菌

目的 建立快速检测肠道侵袭性大肠埃希氏菌（EIEC）的核酸-免疫层析方法。方法 利用不对称聚合酶链式反应技术制备目标单链DNA,结合免疫层析技术分型检测EIEC的毒力基因invE和大肠埃希氏菌标志基因uidA。结果 在不对称PCR体系中,uidA和invE最佳上下游引物比例为1∶3,最佳引物浓度（下游）分别为0.2 μmol/L和0.25 μmol/L,最佳扩增循环次数为40。本方法最低检测限为3.97 × 10^-3 ng/μL的基因组DNA,特异性与PCR-凝胶电泳法相当。结论 本方法具有操作简便、快速、成本低、检测结果准确以及特异性良好等优点,可分型检测EIEC、非EIEC大肠埃希氏菌和非大肠埃希氏菌,适用于基层 实验室使用。     

基于AHP-FEA权重分配方法的码垛机器人腰部转台多目标结构优化

目的:提高码垛机器人的动态性能并降低能耗。方法:通过静、动力学分析确定以质量最小、最大位移最小、第一阶固有频率最大、最大应力最小为优化目标,以结构参数为设计变量,利用Box-Behnken和RSM方法建立目标函数的近似模型;提出一种基于有限元分析结果的层次分析法(AHP-FEA)用于权重系数的分配,并以综合目标函数作为评价指标,利用NSGA-Ⅱ算法求解;基于AHP-FEA方法获得腰部转台的优化模型,并与初始模型进行对比。结果:在保证结构强度、刚度和振动稳定性的情况下,质量减轻了9.6%。结论:与常见的平均分配法和经验赋权法相比,采用AHP-FEA权重系数下的优化综合目标函数值最小,其综合优化效果更优。     

一种基于PCR技术的沙门氏菌血清分型试剂盒与传统血清分型方法比较

目的 评估一种基于PCR技术的沙门氏菌快速血清分型试剂盒效用，并与传统血清学分型鉴定方法进行对比，为研究人员提供一种更高效、简便的沙门氏菌血清学鉴定分型方法。方法 从本实验室菌株库中选取59株沙门氏菌，分别采用沙门氏菌血清分型PCR试剂盒和传统血清凝集法对所有菌株进行分型鉴定，比对两种分型方法的符合率。结果 59株沙门氏菌均通过传统血清凝集方法完成分型，分型率100%。59株菌株均通过沙门氏菌血清分型PCR试剂盒成功分型，分型率100%，两种方法鉴定沙门血清型符合率100%。结论 沙门氏菌血清分型PCR试剂盒能达到较高的分型率，大大缩短检测时间，减少常规血清分型的工作量及昂贵的血清消耗，节约成本，可以作为一种沙门氏菌快速血清分型方法进行应用。     

5种药食兼用菊花挥发性有机物的HS-GC-IMS与指纹图谱

目的：研究菊花品种和产地鉴别、挥发性风味成分特性。方法：以金丝皇菊、皇菊、杭白菊、亳菊、贡菊5种药食兼用菊花为研究对象,利用顶空气相色谱一离子迁移谱,结合聚类分析和关系矩阵,以数据可视化的形式研究不同品种菊花中VOCs指纹图谱的差异性及变化。结果：不同品种菊花之间的VOCs差异明显(P＜0.05) , 两两之间的相似度基本低于70%,且均有其独特的挥发性成分;5种菊花挥发性物质含量由高到低的顺序为：贡菊、金丝皇菊、皇菊、亳菊和杭白菊。结论：HS-GC-IMS能够弥补常规VOCs检测缺憾, 适用于不同品种菊花的区分和鉴定。     

表面增强拉曼光谱法筛查保健酒中那非类药物

目的:利用表面增强拉曼光谱(SERS)技术快速非靶向筛查保健酒中非法添加那非类药物。方法: 制备合适的那非类药物胶体金SERS基底,基底与78种那非类药物混合后进行SERS分析,建立谱图筛查数据库,以匹配度是否高于70%作为评判是否疑似添加那非类药物的依据。最后考察方法的灵敏度和特异性。结果:那非类药物胶体金SERS基底最佳制备方式为98.3 mL超纯水中加入1.0 mL 1%氯金酸和0.7 mL 1%柠檬酸三钠;最低检出质量浓度分别为西地那非0.05 mg/L、他达那非0.5 mg/L、硫代西地那非0.05 mg/L、乙酰伐地那非0.1 mg/L;对模拟样品进行检测,其定性结果与高效液相色谱—质谱法测量结果一致。结论:理论上,该方法可非靶向筛查出保健酒中非法添加的那非类药物。     

HPLC-MS/MS法检测动物源性食品中喹诺酮类药物的基质效应及其补偿措施研究

目的 研究高效液相色谱-串联质谱法（HPLC-MS/MS）测定动物源性食品中15种喹诺酮类化合物的基质效应及其补偿措施。方法 以鱼肉、猪肉和鸡肉作为典型基质,采用提取后加入法和动态多反应监测方式评价基质效应。结果 在三种基质中,60%以上化合物受到中等及强的基质效应,恩诺沙星、培氟沙星和达氟沙星受到强的基质增强效应;氟罗沙星受到强的抑制效应。前处理方法、基质种类、化合物种类以及质量浓度是影响喹诺酮类化合物基质效应的主要因素。结论 日常监测过程中,在不改变检测标准前处理的条件下,采取基质匹配标准曲线、同位素内标、稀释样品以及改善分离度并结合动态多反应监测方式能有效补偿喹诺酮类化合物的基质效应,提高其检测结果的可靠性和准确性。     

基于多光谱特征分区的油桃品质分析算法

目的:解决基于光谱图像识别技术易受相近类型干扰,致使对被测物的种类与品质识别产生偏差的问题。方法:设计了可见光与近红外光的独立双通道光谱采集系统,通过控制不同特征区域的光谱范围与光谱分辨率,实现对特征波长位置的吸光度快速采集;构建了品质参数,给出了其关于光谱变化与样品质量的函数表达形式;根据测试样品的光谱分布特性,选择合适的特征波长位置,并通过主成分分析给出了种类与品质参数的解算依据。结果:采用CM-25D分光仪和FT-NIR分光仪获取了4种常见的油桃样本的可见与红外光谱,建立了以吸光度值与吸光度比值作为判别因子的最小二乘权值分析法,与传统线性比例分析法进行比较,该算法种类识别率均值为96.7%,归一化品质系数为0.892,识别能力均有所增强。结论:采用双通道光谱采集硬件结构配合基于权值分配的偏最小二乘算法,可以对光谱特征相近的油桃品种进行更好的分类与识别。     

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.     

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.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.