白肋烟杂交种及亲本烟碱转化株的鉴别

对我国白肋烟主栽杂交种鄂烟一号和9803调制后烟叶的生物碱组成和含量进行了定株测定,发现存在严重的烟碱向降烟碱转化问题,其中种植历史较长的鄂烟一号的总转化株比例和高转化株比例分别为43.4%和24.5%,都高于新选育的9803。通过对鄂烟一号亲本材料转化株的早期诱导和鉴定,发现作为母本的B21不育系和作为不育系保持系的正常可育的B21群体中都含有极高比例的转化株,分别为81.3%和70.7%,而作为父本的B37转化株较少,为10.9%。因此鄂烟一号的高转化株比例主要由母本引起。对杂交种9803亲本转化株的鉴别结果表明,母本TN86不育系和父本B21低生物碱品系的总转化株占群体的比例分别为40.5%和23.3%,母本对杂交种转化基因的贡献大于父本。      

白肋烟达白杂交种亲本烟碱转化率分析及改良效果

采用烟碱转化株早期诱导鉴别方法,对白肋烟达白系列杂交种及亲本材料不同烟株的烟碱转化率进行了分析测定,并配置了改良杂交种.结果表明,不同杂交种生物碱组成和含量存在显著差异,其中达白1号和达白2号烟碱转化问题相对较小,但群体中仍然不同程度存在转化株,总转化株比例分别为10.9%和23.7%,其中多为低转化株.达白3号问题比较突出,所测烟株全部为转化株,且转化程度较高,多为高转化株,平均烟碱转化率达到38.3%.达白1号的2个亲本MSKYl4和达所26均存在一定比例的转化株.对达白1号群体中转化株的产生均有贡献.达白2号的母本MSVA509多为非转化株,父本达所26对烟碱转化的贡献较大.达白3号父本达所27总转化株比例和高转化株比例都接近100%,是造成达白3号杂交种高烟碱转化株比例的主导因素.严格选择非转化株配置改良杂交种,群体中烟碱转化率显著降低.     

云南宾川白肋烟生物碱含量及烟碱转化率分析

为确定宾川白肋烟生物碱组成特点和品种更新改良的可行性,对云南宾川白肋烟生物碱组成和含量及不同白肋烟品种烟碱转化株比例和烟碱转化率进行了分析.结果表明:宾川白肋烟生物碱含量较低,平均含量为3.31％,与国外白肋烟相似,烟碱转化率较低,烟碱转化问题不突出,且不同试验点降烟碱与烟碱转化率表现出差异性.不同品种烟碱转化率株间分布比较,以OD911和YNBS1烟碱转化问题相对较小,平均烟碱转化率低;TN86大部分为低转化株,烟碱转化率较低;TN90的平均烟碱转化率为11.84％,其中存在10％的高转化株;鄂烟1号烟碱转化株比例较高,有16.67％的高转化株,平均烟碱转化率达30.51％,需要进行系统选择和品种改良.     

2-氯乙基磷酸诱导白肋烟烟碱提前转化的有效性

为评价2-氯乙基磷酸诱导烟碱提前向降烟碱转化的有效性,对湖北和海南两个白肋烟产地的3个白肋烟品种(系)和1个改良品种,进行了2-氯乙基磷酸早期诱导烟碱转化效果研究,并与正常调制的烟叶进行对比分析。结果表明,经过2-氯乙基磷酸处理后,除湖北恩施种植的鄂烟1号外,其余试验品种(系)群体平均烟碱转化率均高于正常调制后的烟叶,其中B21群体平均转化率和高转化株比例高于其它品种;湖北恩施种植的3个品种(系)早期诱导和正常调制在转化株鉴定结果的一致性上比海南高,其中湖北恩施种植的TN90和海南种植的改良鄂烟1号的转化株数超过正常调制出现的转化株数;利用2-氯乙基磷酸早期诱导鉴定筛选留种非转化株,使鄂烟1号后代转化率分别由改良前的22.10%和16.93%降为3.98%,转化株比例尤其是高转化株的比例分别由改良前的48%和27%降为2%。     

旺长期干旱胁迫对白肋烟烟碱向降烟碱转化的影响

通过控制旺长后期土壤水分含量,以研究干旱胁迫对白肋烟中烟碱向降烟碱转化的影响.结果表明,在晾制过程中,不同程度干旱处理导致B37高转化株烟碱转化率的变化存在差异,随烟叶着生叶位的升高烟碱转化率快速增长阶段向后延迟,B37非转化株烟碱转化率整体均维持在较低水平,处理问差异不明显;轻度干旱有利于降低高转化株的降烟碱含量和烟叶(包括转化株与非转化株)的烟碱转化率,提高非转化株烟碱转化性状的稳定性.     

晾制湿度对白肋烟烟碱向降烟碱转化的影响

通过控制烟叶在变黄-褐变期的晾制湿度,研究了晾制过程中湿度对白肋烟中烟碱向降烟碱转化的影响.结果表明,不同晾制湿度下高转化株主脉的烟碱转化率均高于叶片,非转化株除低湿处理B21的第15叶位外,其余处理烟碱转化率表现出与高转化株相同的趋势.高转化株叶片烟碱含量在低湿处理时最高,非转化株叶片烟碱与降烟碱含量皆因品种与叶位的不同而存在差异.无论是高转化株还是非转化株,较低的晾制湿度均有利于降低叶片的烟碱转化率;晾制湿度对烟叶主脉中烟碱、降烟碱及烟碱转化率的影响,因试验品种的不同而异.因此,晾制过程中及时降低晾制湿度有利于降低烟叶的降烟碱含量.     

白花白肋烟与烟碱转化的关系研究

通过对发现的5株白肋烟B37花色突变株后代的连续观察与研究,结果表明,5株白花突变株当代均为高烟碱转化株;随着世代的增加,白花后代群体花色遗传稳定,高转化率性状更趋于纯合;烟株群体的平均烟碱含量明显下降,降烟碱则明显上升,烟株群体生物碱表现为以降烟碱为主。研究认为,在白肋烟品种中,花色由显性向隐性和烟碱转化率由隐性向显性突变,二者关系密切;在白肋烟新品种选育和品种提纯、繁殖过程中,对白色花冠突变烟株应及时发现、淘汰,对烟碱转化株应随世代跟踪检测,严防群体转化株积累和基因逐渐纯合;利用白花烟草突变株进行新品种选育应在明确其烟碱转化情况后,再确定是否加以利用。      

白肋烟生物碱和烟碱转化率的配合力及遗传力的研究

采用Grimng双列杂交第二种设计方法，对4份不同烟碱转化率的白肋烟株系及杂交F1代进行了烟碱、降烟碱和烟碱转化率的杂交配合力和有关遗传参数的研究。结果表明，烟碱、降烟碱和烟碱转化率的表现型方差主要是遗传基因型方差决定的，遗传方差中亲本的一般配合力效应方差和基因加性方差对烟碱转化率的作用最大，在特殊组合中也存在一定的特殊配合力和基因非加性效应。环境方差除对烟碱有一定影响外，对降烟碱和烟碱转化率影响极小。非转化株系亲本的一般配合力效应和非转化株系间的杂交F1特殊配合力效应，在降烟碱和烟碱转化率性状上表现为负向，烟碱为正向；高转化株系则相反。因此，在白肋烟低烟碱转化率育种中选择非转化亲本尤为关键。降烟碱和烟碱转化率为高遗传力性状，对杂交后代进行早世代生物碱和烟碱转化率严格选择是十分必要的。     

打顶及仿生型信号分子对白肋烟不同烟碱转化率株系的影响

为降低白肋烟烟碱转化率、提高烟叶品质,对白肋烟B37不同转化率株系采用打顶和打顶后涂抹仿生型信号分子(BSM)两种方式处理,分别测定了不同处理烟株烟叶的超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、生物碱含量,并分析了生物碱比例和烟碱转化率的变化.结果表明:打顶使不同转化率株系的烟叶SOD活性增加且高转化率株系增加幅度大,BSM处理也增加了SOD活性,但高转化率株系增加幅度较小.打顶使烟株的MDA含量增加,但高转化率株系增加幅度较小;BSM处理后烟叶MDA含量下降,高转化率株系烟叶MDA含量下降幅度较大.BSM处理后烟叶4种生物碱含量及总生物碱含量总体上有所降低,其中降烟碱的降低幅度最大.BSM对非转化株上部叶和中部叶烟碱比例影响较小,而对高转化株系B37-38的作用最大,其上部叶和中部叶烟碱比例分别提高了15.52和10.40百分点;B37-38上部叶和中部叶降烟碱比例分别降低了15.16和10.03百分点.从非转化株系至高转化株系随着烟碱转化率的提高,BSM处理其降烟碱的比例降低幅度增加,BSM对高转化率株系的影响较大.     

白肋烟不同程度烟碱转化株后代烟碱转化率株间变异研究

采用烟碱转化早期诱导方法,对白肋烟达所26及其自交后代不同烟株的烟碱转化率进行了分析测定,以确定烟碱转化株鉴别标准的可靠性和有效性.结果表明,烟碱转化率低于2.5％的烟株自交后代株系稳定,株间烟碱转化率变异小,且均低于2.5％,表明母代烟株为非转化株;烟碱转化率介于2.5％和3％的3个烟株自交后代均表现株间烟碱转化性状的分离,变异幅度分别为0.439％-10.331％、0.466％-21.834％和0.394％-3.757％,表明母代烟株为转化株.烟碱转化率大于3％的烟株自交后代烟碱转化率株间变异性大,烟碱转化性状分离严重;烟碱转化率大于50％的2个烟株自交后代烟碱转化率也都较高,是高转化株的表现.因此,烟碱转化率大于2.5％是确定转化株的可靠标准.     

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