毛细管柱气相色谱法测定食品中微量甜蜜素

研究了测定食品中微量甜蜜素的毛细管柱气相色谱ECD分析方法。结果显示，该法的线性范围是0．01～10．0μg／mL，最低检出限为0.05μg／g，回收率为93.0％～104．0％。     

赭曲霉毒素A直接竞争ELISA试剂盒的研制

在多克隆抗体的基础上研制了赭曲霉毒素A(OTA)直接竞争酶联免疫检测(cd-ELISA)试剂盒.在0 ～ 10 ng/mL范围内,该试剂盒50％抑制率(IC50)为1.09 ng/mL,检测灵敏度(IC15)为0.08 ng/mL;与赭曲霉毒素B、C的交叉反应率分别为6.28％和0.16％,而与黄曲霉毒素B1等生物毒素未见有交叉反应;板内与板间平均变异系数分别为2.21％和2.79％;花生、玉米和玉米粉3种样品中OTA的检测低限分别为1.71,1.26和1.85 μg/kg,平均添加回收率在83.80％～ 91.40％;与HPLC检测方法具有较高的相关性,相关系数(R2)分别为0.94、0.88和0.90;检测时间只需20 min,可用于花生、玉米及玉米粉中OTA的批量快速筛查.     

酶联免疫检测试剂盒检测水产品中孔雀石绿的应用研究

利用酶联免疫试剂盒检测水产品中孔雀石绿残留量,研究了国产试剂盒检测性能,并与高效液相色谱法进行了比较。结果表明：孔雀石绿含量在0．5μg／kg,8μg／kg范围时,试剂盒具有良好线性,最低检出限为0．16μg／kg;试剂盒测得孔雀石绿总量的加标回收率在7l％-120％,批内变异系数介于5．61％-18．6％;检测鳜鱼实际样品时,试剂盒和高效液相色谱法定性判定结果一致,定量结果有所差异,试荆盒测得鳜鱼样品中孔雀石绿残留量为37．75μg／kg,高效液相色谱法测得结果为46．29μg／kg,但准确度偏差范围尚符合国家质量监督检验检疫总局《残留分析质量控制》的要求。综上所述,国产酶联免疫检测试剂盒操作方便快速,灵敏度较高,重现性较好,适用于大量样品的快速检测。     

畜禽肌肉、内脏及虾中磺胺二甲嘧啶残留量的检测技术研究

为了快速、简便、灵敏地监测畜禽肌肉、内脏及虾中的磺胺二甲嘧啶残留，建立了高效液相色谱法快速检测技术。动物组织中的磺胺二甲嘧啶用二氯甲烷超声提取3次，提取液与2％硫酸钠水溶液进行液一液分配，下层有机相经脱水、浓缩后用0．02mol／L盐酸溶解浓缩瓶中残留物，以正己烷去除脂溶性杂质，经0．45μm滤膜过滤后供HPLC测定。结果表明本方法的线性范围为0．2～3．0μg/mL，方法的最低检出浓度为2．1μg/kg，在50～100μg/kg的加标水平，方法平均回收率为76．6％～93．6％，相对标准偏差为4．4％～8．4％。该方法适用范围广，回收率高，检测限低，简单易行，易于在基层推广应用。     

分光光度法测定保健食品中总黄酮的含量

为建立一种检测保健食品中总黄酮含量的快速分析方法，以活性成分芦丁为标准品，在其紫外最大吸收峰415nm处测定其总黄酮的含量。方法的最低检测浓度为0．1μg/mL，芦丁标准品在1．0～25．0μg/mL范围内具有良好线性关系。平均加样回收率为97．62％，相对标准偏差为1．85％。该方法简便，重现性好，可作为检测保健食品中总黄酮含量方法之一。     

转基因食品中Btcry2Ab/2Ac杀虫蛋白直接竞争ELISA试剂盒的研制

研制了用于检测转基因食品中Btcry2Ab/2Ac杀虫蛋白的直接竞争ELISA试剂盒,研究结果表明:该试剂盒的最低检测限为40ng/mL,线性检测范围为40～2000ng/mL,回收率在98.52%～102.27%之间;板内、板间变异系数分别在1.55%～7.17%和3.78%～7.39%之间;试剂盒在4℃下至少可保存6个月以上。     

酶联免疫法检测食品中乳酸链球菌素

建立了酶联免疫吸附法来检测乳制品、肉制品和含乳饮料中的乳酸链球菌素含量。在抗乳酸链球菌素多克隆抗体的基础上,建立间接竞争酶联免疫吸附法。所建立的间接竞争ELISA方法的灵敏度为0.1μg/mL,标准曲线范围为0.1～62.5μg/mL,乳制品的检测限为1.0μg/mL,肉制品的检测限为0.5μg/g,样本的添加回收率范围在80%～120%之间,变异系数<20%。所建立的间接竞争ELISA方法及制备的相关试剂盒具备准确、快速、简便的优点,能够满足乳制品、肉制品和含乳饮料中乳酸链球菌素含量的检测要求。     

固相萃取HPLC法同时测定食品中乙基麦芽酚和香兰素

建立了食品中乙基麦芽酚和香兰素的高效液相色谱测定法。方法采用C18（5μm，4．6mm×250mm i．d）反相色谱柱，流动相为乙腈和0．02mol/L磷酸二氢钠溶液，流速1．0mL/min，检测波长276nm，柱温30℃，进样量20μL。该方法的检出限0．5μg/g-2．0μg/g，测定低限饮料1mg/L,-4mg/L，固态食品为5μg/g-20μg/g，线性范围2．0mg／L～100mg/L，加标回收率97．1％～88．7％，相对标准偏差为4．27％～6．74％（n=9）。     

食品中N-亚硝胺类测定国标方法的改进

本文从样品前处理以及气质联用仪仪器条件两个方面对国标的检测方法进行改进。本文检测方法的各项技术指标均达到国家标准规定的要求,但本文方法比国标方法简单快捷,易于操作,线性相关系数分别可达0．9991、0．9991、0．9990、0．9995;线性范围分别可达0～250μg／mL;方法重现性良好,其RSD可达1．49％～1．94％;回收率可达90．0％～105．0％;灵敏度高,检测限分别为0．04μg／kg、0．025μg／kg、0．05μg／kg、0．01μg／kg。     

ELISA快速测定小麦中硫丹及硫丹硫酸酯

研究应用酶联免疫方法，快速检测小麦中硫丹及硫丹硫酸酯。小麦经80％甲醇提取后，用PBS／T缓冲液稀释5倍后，酶联免疫方法直接测定。方法平均回收率为73．3％～88．8％，线性范围1．5μg／L～25μg／L，最低检测限0．4μg／L，变异系数〈10．03％。经气相色谱／质谱联用方法验证，灵敏度、重现线和准确度均符合快速检测要求。该法具有快速、简便、低耗、易操作等特点。     

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.     

Focus on China's Paper Industry

In the English section of this issue, 〈China Paper Newsletters〉 will introduce ＂National Development and Reform Commission Issued Announcement for Selection of Major Preliminary Research Projects for the ＇13th Five-Year Plan＇＂, ＂2013 Annual Report of China＇s Paper Industry＂, and news of projects and other policies.     

Listen to downstream & search for innovation

正Nowadays,textile enterprises are all taking efforts in transformation and upgrading,like improving producing capacity and optimizing production structure to face market downturn.It claimed a higher request to the standard of textile equipments.In the upcoming of ITMA ASIA+CITME 2014exhibition,this magazine have interviewed several branch associations and a series of relative enterprises,to summarize industrial developing status