不同卷烟机型对烟丝造碎的影响

为分析不同卷烟机型对卷制过程烟丝造碎程度的影响,研究了PROTOS,PASSIM和SUPER9 3种型号卷接机组卷制前后烟丝结构的变化,通过特征尺寸计算不同卷烟机型对烟丝的破碎度,由破碎度分析不同卷烟机型对烟丝的造碎程度。结果表明:①对于同种配方烟丝,PASSIM卷烟机的造碎程度最小,PROTOS卷烟机其次,SUPER9卷烟机对配方烟丝的造碎程度最大;②同一卷烟机型对不同配方烟丝比例的配方造碎程度存在差异,叶丝比例高、梗丝比例低的烟丝经卷烟机卷制后造碎程度高。     

卷烟的卷制水分变化对卷制质量的影响

实验发现,不讼一类卷烟还是一类卷烟,随着烟丝中水分的提高,整丝率变化率均显著增加,即抗碎性提高,一般适宜的卷烟水分应为：一类卷烟１３％,二类卷烟１３．５％左右,不宜过低。卷制过程中整丝率变化率在９２％－９５％的烟丝,抗碎性最佳,同一种烟丝,其整丝率变化率在不同的卷烟机上卷制时不尽相同。进而影响烟支单支重量、空头率,应尽量减少卷烟机后身对烟丝的造碎。     

YJ17卷烟机供丝系统的优化改进

为解决YJ17卷烟机在烟丝松散输送过程中造碎率高、烟丝填充不均匀等问题,对供丝系统进行了优化改进。抛丝辊采用叶片代替螺钉,利用叶片旋转产生风力辅助烟丝拨送,由柔性拨料取代打击式供料;通过降低弹丝辘转速,避免弹丝辘对烟丝结构产生影响,减少烟丝造碎。以蚌埠卷烟厂生产的"黄山(新制皖烟)"牌卷烟烟丝为对象进行测试,结果表明:供丝系统改进后整丝率提高3.9百分点,碎丝率降低0.7百分点,烟丝填充值提高0.05 cm3/g,烟支空头率降低0.09百分点,质量异常烟支剔除率降低24%(670±70 mg),烟支质量标准偏差减少2 mg左右。该技术可为提高供丝均匀性提供支持。     

TR400型残次烟支处理机的工艺改进

针对残次烟支在处理过程中造碎较大、烟丝回收率低、回收烟丝结构差的问题,分析了烟支处理前的温度和回收烟丝含水率对回收烟丝结构的影响.试验表明,当回收烟丝含水率控制在12.9%～13.1%、烟支处理前温度为40～42℃、蒸气压力为0.3MPa,同时将第一次风分后的筛网孔径由4.1mm增至4.9mm,并对流量进行稳定控制的情况下,残次烟支的烟丝回收率提高了42.4%,回收烟丝舍末率降低了48.2%,整丝率提高了41.7%.     

烟丝含水率对细支卷烟的影响

考察了烟丝含水率对细支卷烟烟支物理性能、烟支内部烟丝结构分布、烟支静燃速率、抽吸时燃烧锥落头率、卷烟主流烟气释放和感官质量的影响。结果表明,细支卷烟烟丝含水率为11.5%~13.8%,在卷烟单重一致的情况下,烟丝结构分布、卷烟抽吸时燃烧锥落头率以及感官抽吸品质受烟丝含水率影响大。烟丝含水率增大,烟丝抗造碎性能增强,烟支中大尺寸烟丝所占比例增加,烟末减少,卷烟抽吸时燃烧锥落头现象明显减轻;烟丝含水率从11.5%增加到12.9%,燃烧锥落头率可从65%降低至30%。烟丝含水率过高会导致卷烟烟气浓度减小,满足感降低。此外,烟丝含水率增大,细支卷烟的烟支硬度、烟支静燃速率、烟气焦油和烟碱释放量也会发生细微的变化。综上,建议细支卷烟生产过程中烟丝含水率尽量控制在12.5%~12.9%。     

不同送丝方式与烟丝质量关系的研究

以调研和试验相结合,分析比较了不同送丝方式对烟丝质量的影响,并着重研究和探讨了风力送丝不同工艺参数与烟丝质量的关系。结果表明：①烘后叶丝以皮带送丝造碎最小,风力送丝其次,夹带送丝最多。②贮后烟丝采用挂壁式小车送丝有利于减少烟丝在输送过程中的造碎,优于风力送丝和轨道小车送丝。③在试验范围内,风送速度和距离以及弯头个数与烟丝输送造碎呈正相关关系,随风速、距离和弯头个数增加,烟丝长丝率减少,含末率增加,填充值下降。输送比对风送烟丝质量几乎无影响。④适当提高烟丝温度和水分可减少烟丝风送造碎     

卷烟供丝系统的优化设计

为解决卷烟供丝过程中存在的烟丝造碎大、出料不均匀、产生扬尘影响生产环境等问题,对供丝系统进行了优化改进。储丝柜出料方式采用柔性出料装置代替拨丝辊,将打击式出料改为柔性出料;配丝装置采用筛分式分配圆盘替代离心式匀丝圆盘,可以有效分离出碎丝和烟末。结果表明,卷烟供丝系统改进后,整丝率提高1.43百分点,碎丝率降低0.95百分点;烟支空头率降低0.11百分点,含末率降低0.25百分点;烟支质量标准偏差降低5 mg,吸阻标准偏差降低5.7 Pa。改进后提高了烟丝的纯净度,降低了烟丝配送过程中的造碎,提高了卷烟质量及其稳定性。     

2004和2007年国产不同价类卷烟配方烟丝结构的比较

利用平面旋转偏心式检测筛检测了2004和2007年国产不同价类共计25个牌号(规格)卷烟烟支中的配方烟丝结构,并比较了2004和2007年国产不同价类卷烟配方烟丝结构的差异.结果表明:①2007年国产不同价类卷烟的配方烟丝中大于3.35 mm的配方烟丝较2004年基本呈现减少的趋势.②相比2004年不同价类卷烟,2007年二类、三类和四类卷烟不同尺寸段烟丝比例的标准偏差减小.而一类与五类卷烟不同尺寸段烟丝比例的标准偏差增加.③相同价类、不同牌号卷烟配方烟丝中大于7.10mm的烟丝相比其他尺寸段配方烟丝比例的标准偏差偏大.     

改善CO_2膨胀烟丝结构的探讨

为降低膨胀烟丝的造碎率 ,从改善膨胀烟丝结构的角度出发 ,对美国AIRCOCO2 烟丝膨胀生产线影响膨胀烟丝结构的有关工艺进行了试验分析。结果表明 :①适宜的工艺气体温度和饱和蒸气流量是影响膨胀烟丝结构的重要因素。试验条件下 ,当工艺气体温度为 355℃ ,饱和蒸气流量为 60 0kg/h时 ,膨胀烟丝结构最佳。②适当加大膨胀前的烟丝水分 ,有利于增强膨胀后烟丝的抗碎性 ,膨胀前烟丝水分以 2 2 %为宜。③试验范围内 ,回潮滚筒转速越低 ,膨胀烟丝的造碎率越低。④在膨胀烟丝中施加保润剂 ,能明显增强烟丝的抗碎性     

PASSIM卷接机组供丝系统的改进

PASSIM卷接机组供丝系统采用的机械梳理、定量输送结构,存在烟丝造碎较严重,烟支质量标准偏差较大,空头率较高等缺陷,通过与GD121和PROTOS等卷接机组供丝系统结构原理的对比分析,对PASSIM卷接机组供丝系统进行了改进。①取消初次计量单元中对烟丝造碎严重的计量辊加扩散辊结构;②由定量针辊、计量料槽、小针辊组成二次烟丝计量部分;③重新设计了回丝部分,避免了回丝重复修剪而增加烟丝造碎;④改进了集流管,增加了自动清理功能。改进后PASSIM卷接机组与原机组进行了供丝系统对比测试,结果表明,平均造碎率由17.52%降低到15.31%,烟支质量标准偏差及空头率明显降低,提高了设备运行的稳定性及工艺性能。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

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.     

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

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

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.     

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.