实时荧光PCR定量检测加工产品中转基因玉米Mon810成分

采用实时荧光PCR技术，建立了定量(性)鉴定检测加工产品中转基因玉米Mon810成分的方法。实验设计的可以扩增玉米自身基因和外源基因边界序列的引物和探针具有品种和品系特异性，特异性地检测出食品、饲料等加工产品中转基因玉米Mon810成分。某些检测样品不仅检出转基因玉米Mon810成分，还同时检出其它转基因玉米品系或其它转基因品种。本研究实验建立的转基因玉米Mon810品系鉴定检测方法，即可以用于加工产品中转基因成分的定量检测(检测低限为0．1％)，也可以用于定性检测，或作为常规PCR定性检测后的确证实验方法。     

2011年深圳转基因大豆及其制品的市场占有率和标识情况调查

目的 了解深圳市场转基因大豆及其制品的市场占有率和标识情况,为政府监管转基因大豆提供科学依据.方法 按照监测计划,定期在深圳市场随机抽取大豆及其制品,采用实时荧光PCR方法对其进行定性和定量检测,评估深圳市场转基因大豆的市场占有率和标识情况,并与2006年的监测结果进行比较和分析.结果 2011年共监测样品106份,检出2份转基因阳性样品,市场占有率为1.89％;两份阳性样品中转基因大豆的含量分别为0.93％和0.51％,定量检出限为0.1％.所有检出转基因阳性样品均没有转基因标识;与2006年结果比较,转基因大豆及其制品的市场占有率以及标识情况差异均无统计学意义.结论 目前深圳市场转基因大豆及其制品(食用油脂除外)的市场占有率还很低,并且5年来未发现明显上升;转基因产品标识的管理还有待加强,政府应该加大这方面的执法力度.     

粉碎和膨化工艺对大豆转基因成分及调控元件的影响

以转基因大豆为试验材料,运用定性PCR的方法研究了粉碎、膨化两种加工工艺对转基因大豆内源基因Lectin、外源基因Cp4 epsps以及启动子和终止子的影响。结果表明,粉碎和膨化加工工艺对大豆转基因成分及调控元件的降解有不同程度的影响。     

实时荧光定性聚合酶链式反应标准方法检测转基因产品的验证及应用

目的验证实验室大豆、玉米和水稻及其制品转基因检测方法,并应用于实际样品检测。方法根据GB 19495.4-2018《转基因产品检测实时荧光定性聚合酶链式反应(PCR)检测方法》要求对无转基因标识的样品进行转基因成分检测。结果方法验证满意。40批次样品(大豆、玉米和水稻及其制品)中发现1批次的转基因成分检出,检出率为2.5%。结论市场中绝大部分未标示转基因成分的大豆、玉米和水稻及其制品确实未检出转基因成分,仅有极少数产品含有转基因成分,但未进行有效标识。     

应用PCR-ELISA技术检测转基因产品的研究

建立并优化了转基因大豆与玉米的DNA提取,CaMV35S启动子和T－NOS终止子的序列特点设计特异性引物与探针，应用PCR－ELISA检测技术，建立了转基因大豆与玉米中常用外源基因的快速检测体系，并应用于进出境产品的转基因检测实际工作中。结果表明，建立的PCR－ELISA法具有操作简便，灵敏特异，结果准确的，可对转基因大豆，玉米及其它转基因产品进行定性和定量检测。     

安全

美种植大豆玉米90％以上为转基因品种 美国农业部部长办公室生物技术协调员迈克尔·沙克曼近日表示，美国种植的大豆和玉米90％以上是转基因品种．，转基因农作物在美国的消费非常普遍，如用转基因大豆做动物饲料、豆油，用转基因玉米做乙醇、饲料和加工食品等。他提到，美国超市2／3的食品含有转基因成分，很多美国家庭每天都食用转基因作物加工的食物，如早餐玉米片等。     

我国转基因农产品市场近期状况分析

一　我国正努力提高转基因产品检测技术水平４月初，国内一家著名的新闻机构报道说，自今年３月以来，江苏省出入境检验检疫局农畜产品实验室已成功地从美国和南美进口的８批大豆中检测出转基因成分，这标志着我国转基因产品检测技术取得了重大突破。来自江苏的消息说，农畜产品实验是利用ＣＴＡＢ法提取ＤＮＡ，再利用ＰＣＲ扩增技术检测转基因大豆。据说，按照该方法，如果大豆中转基因成分达到０．１％时就会被发现，含量达到２％时就能够准确检出。在今年初，广东省出入境检验检疫局也曾经宣布对转基因产品具备了检测的能力，但国内媒体…     

食用植物油转基因成分检测技术的研究进展

目前在世界范围内对转基因食品的安全性存在争议,食用植物油转基因成分的定性检测是当前食品检验工作中的一个重要方向。就食用植物油中转基因成分的核酸提取和检测技术的最新进展进行了综述,为后续的检测及研究提供参考,同时指出转基因成分的定量检测将是检验的另一个方向。     

实时荧光定量PCR技术检测腐乳中大豆转基因成分

优化实时荧光定量PCR反应体系条件,运用此技术检测从腐乳中提取的DNA来判定腐乳样品是否含有大豆转基因成分。该检测方法特异性强、灵敏度高,方法检出限为0. 1%,而且操作简便,可以推广使用。     

转基因食品的定量PCR检测方法

近年来转基因食品定性检测方法发展迅速,然而目前转基因成分(GMO)的准确定量检测在国际贸易中日趋重要.我们这里介绍三种定量检测方法半定量PCR法,定量竞争PCR(QC-PCR)法和实时定量PCR法.半定量PCR法比较简单,但结果不是很精确.定量竞争PCR的特点是含有内部标准子.近来开展的实验室合作研究表明,与定性PCR法相比,定量竞争PCR降低了实验室之间的误差.而实时定量PCR法可在提取DNA后3h内,测出每克起始样品的总DNA量及2pg转基因成分的量,但这套PCR系统目前价格昂贵.     

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