大理州烤烟主要化学成分特征及其可用性分析

对大理州主产烟区12个县(市)5个烤烟品种的4个等级(B2F、C2L、C3F和X2F)2077个烤烟样品化学成分特征进行了分析,并应用模糊数学对其可用性进行了综合评价.结果表明:(1)大理州烤烟具有总糖含量(均值为30.9%)以及糖碱比(均值为16.9)较高,氯含量较低(均值0.32%)的特点;(2)大理州烟叶氯离子和钾氯比在等级间差异不显著,总氮含量在品种和产地间差异不显著,其余化学成分在等级、品种、年份和产地间均存在显著或极显著差异;(3)产地间烤烟化学成分可用性指数表现为:宾川>南涧>巍山>弥渡、永平>洱源、祥云>鹤庆、漾濞、云龙>大理>剑川;(4)等级间烤烟化学成分可用性指数表现为:C3F>C2L>B2F>X2F;(5)品种间烤烟化学成分可用性指数表现为:红花大金元>K326>NC82>云烟87>云烟85.     

环秦岭植烟区烟叶主要化学成分特征及其与评吸质量的关系

为明确环秦岭植烟区烟叶主要化学成分特征,采集了环秦岭核心植烟区安康、汉中和商洛C3F烟叶样品共58个,分析了中部烟叶主要化学成分特征,并探讨了主要化学成分与评吸质量的关系。结果表明:1环秦岭植烟区烟叶化学成分整体协调,氯含量偏低,30%的样品钾含量低于1.50%,21%的样品淀粉含量高于6%,32%的样品两糖比低于0.75。淀粉含量较高,钾、氯含量及两糖比偏低是影响环秦岭植烟区中部烟叶化学成分协调性的主要因素。2不同产区间烟叶化学成分的主要差异表现为安康烟叶烟碱含量相对较低而糖碱比和氮碱比较高,汉中烟叶烟碱和淀粉含量显著提高,商洛烟叶钾含量和钾氯比相对较低。3总氮、氯含量和两糖比是影响该植烟区中部烟叶评吸质量的主要化学成分;在试验范围内,随着总氮含量的降低、氯含量和两糖比的提高,烟叶评吸质量逐步得到改善。因此,环秦岭植烟区应从降低总氮含量、适当提高氯含量和两糖比等方面改善烟叶化学成分协调性,提高烟叶品质。     

山东烟叶的品种和化学成分与其感官质量的相关分析

对山东烤烟综合品质进行评价,采用灰色关联法对4个品种烟叶(C3F)的化学成分与感官质量进行相关性分析.结果表明:总氮、烟碱、还原糖、总糖、糖碱比与香气质、香气量、余味、杂气、刺激性等均呈正关联;烟叶品种对内在感官质量影响大小的顺序为NC89＞云烟85＞K326＞NC82.     

湖南旱地和稻田陈化烟叶品质差异性对比分析

湖南烟区大部分是烟-稻轮作,为研究旱地烟叶和稻田烟叶品质的差异,笔者采用近红外无损检测法测定了湖南旱地和稻田陈化烟叶常规化学成分的含量,并进行感官评吸.对所测数据的t-检验结果表明,还原糖、总糖、烟碱、氯含量和氮碱比差异显著.评吸结果显示稻田烟叶的总体得分较高.稻田烟叶化学成分和评吸质量的典型相关主要是由化学成分中的烟碱、还原糖、总氮、氮碱比、糖碱比和评吸质量中的劲头、浓度、香气量引起.旱地烟叶化学成分和评吸质量间的典型相关主要由化学成分中的烟碱、总糖、还原糖、糖碱比和评吸质量中的劲头、香气量、刺激性、燃烧性引起的.说明稻田烟叶和旱地陈化烟叶品质间存在一定差异.     

云南烟区烤烟品种K326主要化学成分特点分析

对云南省主产烟区烤烟品种K326主要化学成分进行分析,并与津巴布韦烤烟化学成分进行比较.结果表明:云南烤烟K326主要化学成分总体协调,总糖含量、还原糖含量较高,总氮含量、烟碱含量、氯含量、糖碱比、氮碱比、钾氯比均较适宜,氯含量的变异系数最大,总氮含量的变异系数最小;K326烤烟不同等级间差异显著,钾含量、氯含量和钾氯比在不同等级间差异不显著,钾含量、糖碱比、钾氯比在不同地区间差异显著,其他化学成分指标在不同地区间差异不显著;K326烤烟的总糖含量、还原糖含量、钾氯比显著高于津巴布韦烤烟,其氯含量、氮碱比显著低于津巴布韦烤烟.     

云南省临沧烟区烤烟化学成分特征及空间分布

为了解云南省临沧市烤烟化学成分特征与空间分布,测定了临沧市7县1区的B2F,C3F,X2F 3个等级189个烤烟样品还原糖、总糖、烟碱、总氮、钾与氯含量,并应用模糊数学、多元统计分析与地统计学方法进行数据分析。结果表明:①临沧市烤烟总氮、烟碱、钾、氯含量以及钾氯比均在适宜范围内,总糖、还原糖含量和糖碱比稍高,氮碱比略低。②等级间除还原糖与氯外,其余指标差异显著;品种间仅总糖与氯差异显著;县(区)间除总氮外,其余指标差异显著。③临沧大部分烟区的烟样化学成分综合指数较高,其中,镇康县、沧源县与临翔区化学成分综合指数最高,凤庆县最低。     

广东浓香型烤烟主要化学成分的变异分析

对2003—2006年广东省主产烟区烤烟主要化学成分含量进行了变异分析,结果表明:广东烤烟总糖含量、还原糖含量及糖碱比总体较高,烟叶氯含量较低且变异性较大,钾氯比较大但表现欠稳定.广东烤烟不同等级间除氯含量和钾氯比差异不显著外,其余各指标差异均达到显著水平;不同品种烤烟除钾含量和总氮含量外,化学成分差异均不显著;年际间氯含量及钾氯比表现较不稳定;不同地点间化学成分差异极显著.广东烤烟与津巴布韦烤烟化学成分存在显著差异,但就上部叶而言,两地烤烟主要化学成分含量相近.     

湖北烤烟主要化学成分年度间稳定性分析

采用统计分析方法,对湖北烟区18个植烟县的2005—2009年共计234个初烤烟叶B2F、C3F、X2F样品的主要化学成分进行了稳定性分析。结果表明:(1)湖北烤烟化学成分平均值基本都在优质烟的适宜值范围内,总糖、还原糖、总氮的变异较小,氯、钾氯比、糖碱比的变异较大。(2)湖北烤烟主要化学成分变异性在各年度表现不同,各年份各部位等级烟叶主要化学成分含量变异不同。总体来看,年度内氯、两糖差的变异较大,总氮、还原糖、总糖的变化较小。(3)湖北烤烟B2F等级年度间总糖、总氮、钾、氮碱比、糖碱比达到极显著差异;烟碱、钾氯比达到显著差异。C3F等级年度间总糖、总氮、氮碱比、糖碱比、钾氯比达到极显著差异;烟碱、氯达到显著差异。中上部烟叶的烟碱呈下降趋势,钾含量呈上升趋势。X2F等级年度间总糖、总氮、钾、糖碱比、钾氯比达到极显著差异;烟碱、氯、氮碱比达到显著差异。     

云南宣威初烤烟叶叶形特征与内在品质的关系研究

为了探索云南宣威烟叶叶形特征与主要化学成分及感官评吸质量的关系,采集云南宣威127份中部烟叶样品,测量烟叶长度、宽度、单叶重,测定主要化学成分含量,并对感官评吸质量进行了鉴定。结果表明,在一定范围内,随叶片长度增加,烟叶总糖、还原糖、淀粉含量和糖碱比、氮碱比降低,总氮和总植物碱含量增加。随叶片宽度增加,烟叶总氮含量显著降低。随叶片长宽比减小,烟叶总糖、还原糖、淀粉含量和糖碱比、氮碱比显著升高,总氮和总植物碱含量显著降低。随单叶重增加,烟叶钾含量、氮碱比显著降低。相对而言,叶片长宽比对烟叶感官评吸质量影响最大,其次为烟叶宽度和单叶重。本研究取样范围内,云南宣威烤烟叶片长宽比偏大,可能是影响烟叶内在质量进一步提高的主要限制性因素。     

重庆烤烟化学成分与感官品质典型相关分析

为明确影响重庆烟叶感官品质的主要化学因子,以烤烟品种云烟87为材料,采用典型相关分析方法研究了烟叶的主要化学成分与感官品质的关系。结果表明,重庆烤烟的糖分含量偏高,烟碱、总氮、淀粉含量适中,钾、氯含量偏低;两糖差、糖碱比偏大,两糖比和钾氯比适中,氮碱比偏小。典型相关分析显示,劲头与总氮、烟碱呈正相关,与糖碱比呈负相关;刺激性与钾含量和糖碱比呈正相关,与总氮、烟碱含量呈负相关;甜度与淀粉含量呈负相关,与糖碱比呈正相关;透发性与淀粉含量呈负相关。因此认为,糖分、总氮、烟碱、钾和淀粉是影响重庆烤烟感官质量的关键因素。     

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.