降低溶耗之我见

浸出油厂的溶剂损耗,主要是从粕、毛油、废水、尾气中带走和跑冒滴漏。溶剂消耗高,直接影响企业的经济效益,浪费能源,同时也带来许多不安全的因素。因此,把好湿粕脱溶烘干、毛油、废水、尾气、跑冒滴漏这五关,降低溶剂消耗,确保安全生产,对于浸出油厂极为重要。 一、粕脱溶烘干关 浸出后的湿粕,靠高料层蒸脱机蒸脱溶剂,而控制蒸脱机气相温度,则十分重要。气相温度高了,粕末会堵塞管道阀门,粘附冷凝器列管,降低冷凝器的冷却效果,使系统内压增加,分水器易跑溶剂,影响正常生     

管束蒸脱机的结构原理与实际应用

从介绍DT蒸脱机入手 ,阐述了管束蒸脱机的结构、原理及应用特点。这种蒸脱机出粕色泽浅、不结团、香味大 ,且能耗低 ,作为 5 0t/d - 6 0t/d的小型蒸脱机已经取得了成功 ;如何进一步把它开发成大型蒸脱机 ,生产专用粕 ,尚待进一步研究。     

蒸脱机的改革设计

蒸脱机是蒸脱浸出湿粕中溶剂的主要设备。蒸脱工艺和设备设计是否合理,直接影响到蒸脱浸出湿粕的效果,是回收利用溶剂、降低浸出工段溶剂单耗的主要关键之一。浸出湿粕中一般含溶剂在25～30％左右,含水8～9％左右,含油1％以下,湿粕经蒸脱机蒸脱后,成品粕中主要技术指标:粕中残余溶剂800PPm以下,粕中水份在10～11％左右;粕色泽正常。我厂设计的国内无类型的新型蒸脱机自1984年1月试车投产以来,各项主要技术指标据测定数据证明:此工艺和设备的设计是合理的,完全达到技术设计要求;投产     

混合油负压蒸发工艺探讨

浸出毛油的品质随着加热温度的升高和时间的延长显著降低,混合油负压蒸发工艺是使一蒸、二蒸、汽提在负压状态下操作,同时,利用蒸脱机的二次蒸汽作为一蒸的热量来源.一方面在负压状态下可以减少油脂与空气中氧分子的接触;另一方面可以降低混合油中溶剂的沸点,以达到降低蒸发温度的目的.可以节约能源、节省钢材、提高毛油质量.在负压蒸发工艺设计中要注意合理配备冷凝面积,降低冷却循环水的温度,防止蒸脱机气相产生正压,控制蒸脱机二次蒸汽量,合理操作第二蒸发器,使用湿式粕末捕集器,加大第一蒸发器面积,列管适当加长加大,并选用不锈钢材质,选择蒸汽喷射泵,合理选择真空度,搞好余热利用和尾气回收.     

蒸脱机的结构改进与优化设计

蒸脱机是浸出车间重要的设备之一,介绍了蒸脱机的工作原理,并结合生产实践,对蒸脱机的结构进行了改进和优化,强化了蒸脱层二次蒸汽对湿粕的自蒸作用。通过对蒸脱机结构的改进和优化,节约了蒸汽消耗,提高了棉籽粕的质量。     

蒸脱机正压的原因分析

蒸脱机是油脂浸出车间的重要设备,它的设计与操作不仅关系到粕的质量,同时也关系到加工成本、经济效益和车间的生产安全.蒸脱机正压会造成溶剂汽体从封闭绞龙、湿粕刮板等处泄漏,严重影响车间的生产安全.     

小型油厂DT蒸脱机冷却工艺改造实践

介绍了小型油厂的DT蒸脱机冷却工艺改造。对现有浸出油厂使用的DT蒸脱机的烤粕区间接汽夹层设置冷却水循环控制系统,间接汽夹层通过导入冷却水对脱溶后的粕进行冷却。同时在原烤粕区的拔汽筒上设置小型防爆变频引风机通过强制吸风调节粕的含水量。改造后的工艺干粕温度可控制在40℃以下,水分含量11.5%以下,干粕可直接灌包缝口码垛。该工艺在改善劳动环境和劳动强度的同时,也简化了操作工序,节约了蒸汽和水,从DT烤粕区导出的热水也可用于其他小范围的采暖,经济和社会效益比较明显。     

对DT式蒸脱机结构的几点改进

目前，大豆一次性浸出法制油发展很快，而且无论大小厂家，蒸脱工序大多采用DT式蒸脱机。DT蒸脱机的功能是：脱除湿粕中的溶剂，并使粕中有害毒素得到有效的破坏后，获得优质豆粕，但我厂使用的DT式蒸脱机结构复杂，制造条件要求高、动力消耗大、蒸汽耗用大、出粕水分高等弊病。为此，通过查阅有关资料，并结合生产实践进行如下改进，收到良好效果。1加高蒸脱机上部机体蒸脱机上部脱溶区，有一个扩大的拱顶盖，是使混合蒸汽到达顶部时速度降低，从而减少混合蒸汽带出粕末的含量，然后再通过粕末捕集器，使混合蒸汽的粕末含量再次降低，以…     

对蒸脱机利用过热水蒸汽脱溶时结构探讨

通过对过热水蒸汽在颗粒固相层中进行水蒸汽蒸馏的特性分析,结合生产实践根据对不同结构型式蒸脱机刮用过热不蒸汽脱溶效果对比,认为利用过热水蒸汽脱除湿粕溶剂时,蒸脱机应具备合理结构。     

提高菜籽粕产出率的途径

菜籽粕的开发和应用越来越引起业内人士的重视。近年来它在市场上很走俏 ,价格也不低 ,这对于浸出油厂来说是十分有利的 ,但如何提高菜籽粕的产出率 ,将直接关系到油厂的经济效益。大家都知道经高料层蒸脱机出来的菜籽粕温度都在 10 5℃— 110℃之间 ,水分只有 7%— 8%。这时的粕即使经过较长输送设备运至粕库后 ,温度仍然很高 ,且粕粉末很大到处飞扬无法回收 ,粕库工作人员的工作环境十分恶劣。如果将此粕强行进行装袋或大堆储存 ,则势必导致菜籽粕结块、发红 ,还有可能存在火灾隐患。我厂针对以上问题自行研制出一台密闭搅拌罐 ,(见右图 )…     

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