基于离散元的辊式磨粉机齿辊功率研究

目的:优化辊式磨粉机I皮磨小麦制粉操作参数,降低制粉能耗。方法:利用EDEM离散元仿真软件,对轧距、喂料量、转速及转速比等关键制粉因素设计Box-Behnken试验,探究操作参数与制粉功率的关系。结果:对齿辊破碎功率影响的显著性排名依次为：转速比、轧距、喂料量、转速比二次项、轧距二次项、轧距和转速比交互、喂料量和转速比交互、轧距和喂料量交互。根据I皮磨粉机出粉要求不同,得到最优参数组合：较细出粉时轧距为0.67 mm、喂料量803.60 kg/(cm·d)、快辊转速537.68 r/min、转速比2.64。较粗出粉时得到低功耗的最佳轧距为0.79 mm、喂料量803.83 kg/(cm·d)、快辊转速576.08 r/min、转速比2.23。结论:仿真模拟结果与实测结果误差在合理范围内,建立的离散元制粉模型可用于小麦制粉时的功率预测。     

关于Ⅰ皮磨小麦流量的研究

本文主要通过布勒—米亚格实验磨粉机将小麦进行头道研磨试验,并对磨研物料作筛理分析和品质测定。以138个试验所得到的测定数据作为依据来说明Ⅰ皮喂料量与磨辊的转速、排列、速比、轧距、动耗、各物料之间的配比和品质之间的关系。这些试验结果给于理论研究和实际操作提供参考。     

对辊式磨粉机在魔芋精粉加工中的应用

对辊式磨粉机是加工魔芋的一种有效设备。影响魔芋颗粒研磨质量因素有磨辊转速、喂料量、轧距、温度环境。本文主要研究对辊式磨粉机轧距对魔芋颗粒研磨质量的影响,通过轧距调节系统中慢辊轴承座和可动偏心轴的受力分析,分析结果得出设计角度α在45°附近,可动偏心轴能达到自锁条件,使对辊式磨粉机在工作状态下轧距保持稳定,为优化对辊式磨粉机在魔芋精粉加工中的应用提供理论基础和参考依据。     

信息荟萃

制粉工段向动调节系统据粮油储运科技与经济信息报道，意大利奥克利姆公司开发出了制粉工段的自动调节系统。这个系统能自动遥控磨辊轧距，传感器可以测量磨辊的位置和电机功率。这个系统根据预定的和实际的筛上物数量之间的比率，可对每对磨辊进行距离调节。磨粉机上带有喂料和来自平筛的筛上物流检测装置，此系统连同磨粉机和料流检测装置一起，可将正确的磨辊轧距数据传送到所控制的每一台磨粉机，将实际的筛上物比例准确地维持在面粉生产者用程序设定的数值上，这种自动控制用在第一道皮磨上时是很有好处的，用于后路研磨或重磨通道，位…     

浅议磨粉机操作工的职责

正一个好的磨工要熟悉制粉工艺流程,制粉设备的工作性能,电路气路的基本工作原理等,才能保证车间的正常生产与产品质量稳定。1)研磨操作要点①喂料是磨粉机研磨的第一环节,物料必须均匀的分配到磨辊长度上,比较薄的料流入磨辊的轧距内。物料若没能沿辊长均匀分布,不但会降低研磨效果,而且磨辊易产生磨损。皮磨的物料粗大,呈大片状,流动性差易结拱,可调节拉力弹簧,使皮磨物料在料筒内保持一定的高度,心渣磨物料呈现颗粒     

浅议磨粉机操作工的职责

<正>一个好的磨工要熟悉制粉工艺流程,制粉设备的工作性能,电路气路的基本工作原理等,才能保证车间的正常生产与产品质量稳定。1)研磨操作要点①喂料是磨粉机研磨的第一环节,物料必须均匀的分配到磨辊长度上,比较薄的料流入磨辊的轧距内。物料若没能沿辊长均匀分布,不但会降低研磨效果,而且磨辊易产生磨损。皮磨的物料粗大,呈大片状,流动性差易结拱,可调节拉力弹簧,使皮磨物料在料筒内保持一定的高度,心渣磨物料呈现颗粒     

布勒法——硬麦实验制粉条件的优化

以郑麦9023为硬麦样品,利用布勒实验磨进行实验制粉并进行制粉评分。正交实验表明,布勒法硬麦最佳制粉条件是磨辊轧距1的设置下,润麦水分16/,润麦时间24h,样品喂料速度为120~130g/min之间。     

八辊磨粉机研磨效果的研究

在实际生产中对八辊磨粉机1皮,2皮进行研磨试验,通过流量的变化及1皮与2皮轧距的组合,测得不同工况下的研磨剥剥刮率,取粉率,耗用电流,研磨物料粒度分布及分级的物料的灰分,研究在原料,磨粉机技术参数相对稳定的条件下,流量,轧距对研磨效果的影响,为八辊粉机的使用和操作,及小麦制粉工艺设计提供依据。     

先进的三辊式粉碎机的设计

辊式磨粉机(或粉碎机)在饲料厂和面粉厂得到广泛使用。粉碎过程的各个步骤都采用一对水平安装的磨辊。两个磨辊并排装置,轧点处留有适当的间隙两磨辊相向转动——左边的磨辊顺时针方向转动而右边磨辊为逆时针方向转动—物料从上方落入轧点。轧点处的研磨作用取决于磨辊和物料的特性、轧点处轧距的大小以及磨辊的转速。在面粉厂,各道工序采用1台辊式磨粉机,研磨过程重复多次。磨粉机也可用     

白口铁抗小麦籽粒粉料的磨料磨损试验研究

为了研究小麦粉加工时,辊式磨粉机磨辊与物料之间的磨料磨损状况,本研究选用与辊式制粉工况相似的磨料磨损试验机,应用正交试验法考察了小麦籽粒粉料粒度、转速和轧距对白口铁磨损性能的影响,采用扫描电子显微镜对其磨损表面形貌进行观察。结果表明,磨料粒度对白口铁磨损性能的影响极为显著,磨损的主要形式有塑变疲劳剥落、多冲疲劳磨损和脆性剥落。研究结果可为提高磨辊的耐磨性和减少加工过程对面粉的金属污染提供参考。     

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