烟梗预处理工序工艺参数优化

采用单因素试验和正交试验的方法,优化了烟梗预处理的工艺参数,分析了烟梗含水率标准偏差稳定性的影响趋势.结果表明:当洗梗时间60 s,洗梗水温60℃,蒸梗温度80℃,贮梗时间3 h时,烟梗回透率提高到99.3%.     

预处理工艺对烟梗回透率的影响

以烟梗回透率指标为参考,在单因素试验基础上,运用四因素三水平响应曲面分析法,研究梗丝生产制造过程中梗预处理段工艺参数对烟梗回透率的影响。结果表明,贮梗时间、浸梗时间、蒸梗温度、浸梗水温对烟梗回透率影响显著,建立二次回归方程模型,模型显著、有效;梗预处理段最佳生产工艺为浸梗时间70s,浸梗水温60℃,贮梗时间3.5h,蒸梗温度60℃。该条件下,烟梗回透率最高。     

水槽式烟梗回潮机温度精准控制系统的设计

由于水槽式烟梗回潮机温度控制系统受水位波动影响较大,造成水温波动,影响出口物料温度和含水率的稳定性。通过分析水温波动原因,对水槽式烟梗回潮机的加水、排水及加热管路进行了改进,将水位、水温控制模式由上下限控制改为PID闭环控制。结果表明:改进后的水槽式烟梗回潮机避免了水位周期性波动,有效提高了水温的稳定性。以水温60℃进行对比测试,温差由±5.52℃降低至±1.43℃,标准偏差由1.02℃降低至0.62℃。水温的精准控制保证了出口物料温度和含水率的稳定性,满足了梗丝生产的工艺需求。      

造纸法烟草薄片萃取技术研究

萃取是造纸法烟草薄片制造工艺中的关键工序之一。烟梗、烟末用水萃取,考察了萃取温度、料液比、萃取时间等对萃取率的影响。结果表明,烟梗最佳萃取工艺条件为:萃取温度60℃,料液比1:5,萃取时间70min;烟末最佳萃取工艺条件为:萃取温度50℃,料液比1:5,萃取时间50min。在最佳萃取工艺条件下,烟梗和烟末的萃取率分别为48.52%和53.76%。     

Tween-80在造纸法烟草薄片萃取工艺中的应用

萃取是造纸法烟草薄片制造工艺中的关键工序之一。烟梗、烟末用水萃取。萃取时加入表面活性剂聚氧乙烯山梨醇酐单油酸酯(Tween-80)以提高其萃取率。考察了Tween-80添加量、萃取温度、料液比和萃取时间等对萃取率的影响。结果表明,优化后的烟梗萃取工艺条件为:Tween-80添加量0.1%(相对于绝干原料的质量,下同)、萃取温度60℃、萃取时间70 min、料液比(原料与水的质量比,下同)为1:5;优化后的烟末萃取工艺条件为:Tween-80添加量0.1%、萃取时间50 min、萃取温度50℃、料液比1:5。在优化后的萃取工艺条件下,烟梗和烟末的萃取率分别为49.67%和54.82%,有效地提高了萃取率。     

造纸法再造烟叶提取工艺优化的研究

为优化再造烟叶提取工艺,本文研究了料液比、提取时间、提取温度对烟梗及烟叶提取率的影响,采用正交实验优化了工艺参数,结果表明:在料液比1∶6、提取水温75℃、提取时间40min的条件下,烟梗提取率最优,达到37.08%;在料液比1∶12,提取水温85℃,提取时间40min的条件下,烟叶提取率最优,达到35.91%。     

造纸法烟草薄片萃取技术研究

萃取是造纸法烟草薄片制造工艺中的关键工序之一。烟梗、烟末用水萃取,考察了萃取温度、料液比、萃取时间等对萃取率的影响。结果表明,烟梗最佳萃取工艺条件为：萃取温度60℃,料液比1：5,萃取时间70min;烟末最佳萃取工艺条件为：萃取温度50℃,料液比1：5,萃取时间50min。在最佳萃取工艺条件下,烟梗和烟末的萃取率分别为48．52％和53．76％。     

烤烟打叶复烤片烟皱缩率影响因素研究

为提高烤烟打叶复烤的加工质量,通过试验调查了叶片中含梗率、叶片回潮区加入蒸汽的压力和蒸汽量对复烤叶片皱缩率的影响。结果表明,叶中含梗率与皱缩率成负相关线性关系,叶中含梗率上等烟≥1.11%、中等烟≥1.23%、下等烟≥1.46%时,叶片皱缩率均达到国标中皱缩率的要求;在(12±1)%水分要求的情况下,减少蒸汽用量,增加高压泵加水量可以减少皱缩率,增加叶片回潮时的伸展性。     

烟梗双螺杆制浆机直接成丝工艺及其应用

为研究烟梗预处理条件对双螺杆搓丝机成丝效果的影响,考察了汽蒸时间,汽蒸后烟梗水分,烟梗搓丝段数对烟梗成丝得率的影响。实验结果表明:调节烟梗初始水分为40%~50%进行汽蒸处理,随着汽蒸时间的延长,烟梗水分迅速增加,水分由初始值增加到58.14%,10 min以后烟梗的水分变化趋于平缓,因此确定10 min为烟梗较佳的汽蒸时间;烟梗初始水分控制在40%~50%,汽蒸处理后水分达到55%~60%,该条件下烟梗搓丝效果最好;汽蒸后烟梗单段搓丝,梗丝合格率为48.63%,经过3、4段的搓丝,过细的梗丝造成梗丝缠绕,合格梗丝过筛困难,合格率下降,并且产生了很多细碎组分。因此,烟梗汽蒸成丝的最佳处理条件为:烟梗回潮后水分40%~50%,最佳汽蒸时间10min,汽蒸后水分达到55%~60%,两段搓丝,在此条件下,合格梗丝得率为68.91%。     

不同加工方式烟梗的物理保润性能对比分析及应用

为了研究梗条、梗片的物理保润性能以及烟梗复烤和制梗丝工艺的差异性,采用动态水分吸附法,利用Weibull模型对数据进行拟合,以特征时间α参数值的大小作为物理保润性能差异性评价指标,分析了梗条、梗片的保润性能、吸水率、失水率的差异;通过加工工艺对比,分析了两种加工工艺的生产效率、能耗、物理质量、感官质量等指标差异。结果表明:①与梗条相比,在相同温湿度条件下,梗片吸水率和失水率均大于梗条,梗片吸湿、解湿速率较快。②与传统梗条复烤、制梗丝工艺相比,梗片复烤烤梗机设备温度降低了7.0℃、梗片复烤生产效率提升了30.51%;梗片制梗丝工序生产效率提升了20.75%;每生产1000 kg梗原料,梗片综合能耗标煤下降了2.20 kgce;节约生产时间2.11 h。③与采用梗条制成的梗丝样品物理指标、感官质量相比,采用梗片制成梗丝的出梗丝率和填充值分别下降了6.82百分点和0.99cm^3/g;而梗片梗丝样品在香气质、杂气、余味等方面有改善,总体感官质量有提升。研究结论可为优化制梗丝工艺,缩短加工时间,提高制梗丝生产效率提供参考依据。     

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.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

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.     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the