二混蜜中钾的离子交换柱层析法分离和回收

在制糖工业中钾是一种影响糖分回收的造蜜剂.提出以离子交换柱层析分离和回收二混蜜中钾盐的新思路,研究了钾在离子交换层析柱上的分离和洗脱工艺条件.结果表明,实验条件下BK001树脂在层析柱中吸附K+的最佳的工艺条件为:操作流速2 BV/h、锤度50°Bx、温度60℃、高径比为8:1;各工艺条件对钾的分离影响大小顺序是:高径...     

糖用钙型离子交换树脂的制备及其脱盐特性

制糖二混蜜中含有大量造蜜剂K~+和Na~+需去除,以提高糖分回收率.本文比较了7种钠型阳离子交换树脂的钙富集能力,以及各转型钙离子交换树脂的二混蜜脱钾钠能力,并对选定用于二混蜜脱钾钠的树脂吸附、解析性能和粒度分布进行了研究.结果表明,钠型阳离子交换树脂BK001可富集29.2mg Ca~(2+)/mL树脂,二混蜜中钾钠对Ca~(2+)的解析率最高可达91.7%,有着典型的吸附和解吸曲线,脱钾钠前后树脂粒度分布变化不大,适于转型为钙离子交换树脂后用于二混蜜脱钾钠.     

钙和镁型离交树脂的制备及其二混蜜脱盐

比较了镁型和钙型离子交换树脂的制备及其对二混蜜脱钾钠的效果,探讨钙型树脂替代耗用大量Mg^2＋再生剂的传统镁型树脂对二混蜜脱盐以提高糖分回收率的可行性。结果表明,相同的静态吸附和洗脱条件下,钠型BK001树脂对Ca^2＋的吸附量大于Mg^2＋,但Mg^2＋型树脂对二混蜜脱钾钠效果稍好于Ca^2＋型树脂;动态的钙型树脂对二混蜜脱钾钠效果好于静态的镁型树脂。故钙型BK001树脂可用于二混蜜脱钾钠的糖分回收工艺。     

中药提取物中重金属离子的去除方法研究

采用001×7强酸性阳离子交换树脂,对中药提取物中有害重金属离子pb2+、Cd2+、Cu2+进行吸附去除试验,并检测离子交换处理对其黄酮含量回收率的影响.结果表明:001×7强酸性阳离子交换树脂对于中药提取物所含重金属离子pb2+、Cd2+、Cu2+去除效果显著,黄酮回收率为95.3～97.9％.001×7强酸性阳离子...     

低度海红果酒离子交换法降酸工艺

为解决工业生产中海红果酒有机酸含量较高的难题,试验研究了离子交换树脂对低度海红果酒的降酸效果及其影响因素。采用6种离子交换树脂对海红果酒进行吸附降酸,通过测定吸附前后海红果酒的主要理化指标,筛选出降酸效果最佳的树脂。研究了最佳的离子交换树脂的静态吸附和动态吸附试验。结果表明,A451弱碱性阴离子交换树脂是低度海红果酒的最适降酸树脂;A451离子交换树脂与酒样以1∶20的比例静态吸附300 min后,树脂达到吸附平衡,此时树脂对总酸的表观交换吸附量为0.128 g/g;温度对海红果酒离子交换法降酸影响不明显;流速对A451离子交换树脂吸附降酸有显著的影响,较低的流速可以获得较大的处理量,A451离子交换树脂的最佳作用流速为3 BV/h。     

离子交换树脂提取糖蜜酒精废液中K^＋的研究

选用5种强酸性阳离子树脂：树脂BK001、树脂S-9、树脂ZGC108、树脂D001和树脂001×7对糖蜜酒精废液中的K^＋的吸附性能进行研究。静态吸附、等温吸附及吸附和洗脱的动力学研究显示,树脂BK001和树脂ZGC108适合糖蜜酒精废液的K^＋的分离。本研究提供一种新的K^＋提取来源,为有效利用糖蜜酒精工业废弃物及实现提K^＋的工业化生产提供基础理论依据。     

732型大孔阳离子交换树脂对铅吸附性能的研究

通过树脂对铅的吸附作用可富集低浓度溶液中的铅,这对食品中铅的检测有重要意义。以铅离子的吸附率为指标,通过筛选试验,从732型、D113型离子交换树脂中筛选出732型阳离子交换树脂;研究树脂用量、吸附时间、铅溶液浓度、转速、温度、pH值等因素对732型阳离子交换树脂吸附效果的影响。结果表明:吸附时间、温度、铅溶液浓度和pH值对吸附影响较大;树脂吸附铅的最佳条件:树脂质量8g,铅浓度10mg/L,交换温度30℃,当铅溶液的pH值为5.85,吸附时间3h,铅的吸附率达到94.5%。     

树脂柱层析法分离纯化籽瓜中L-瓜氨酸

目的:研究适合分离纯化籽瓜L-瓜氨酸的树脂柱层析方法。方法:选择001×7、D001和D061三种阳离子交换树脂进行L-瓜氨酸静态吸附解析和动态平衡实验,优化分离提纯籽瓜L-瓜氨酸工艺。通过考察温度、p H、浓度、吸附穿透曲线及洗脱液浓度、流速因素,进一步研究001×7树脂层析柱分离纯化籽瓜L-瓜氨酸的条件。测定三种不同极性大孔吸附树脂和活性炭对籽瓜提取液的脱色率和吸附率,优化脱色工艺。结果:分离提纯籽瓜L-瓜氨酸工艺用001×7型阳离子交换树脂较适合,最佳工艺条件:上柱温度为40~50℃,上柱液的p H为3,洗脱液选择0.5 mol/L的氨水,洗脱流速为0.5 m L/min,洗脱液的用量为6倍树脂体积。脱色工艺使用HZ-801大孔吸附树脂较合适,脱色精制后可得到纯度为96.6%的L-瓜氨酸产品。结论:001×7型阳离子交换树脂层析柱和HZ-801大孔吸附树脂相结合,可以有效分离纯化籽瓜中的L-瓜氨酸,对充分利用籽瓜资源和改变我国L-瓜氨酸成本较高现状具有十分重要的意义。     

阴离子交换树脂的粒径和吸附时间对植酸吸附容量的影响

717型阴离子交换树脂的粒径大小和吸附时间长短对植酸在该树脂上的吸附容量有很大影响.通过离子交换的吸附实验,测定植酸在717型阴离子交换树脂上的吸附数据,利用统计分析理论对实验结果进行分析,得出了植酸吸附容量同阴离子交换树脂的粒径与吸附时间之间的统计分析模型和三维曲面图,并确定直径≤20目的阴离子交换树脂进行吸附实验的实验效果较好.     

离子交换装置试制及脱除鱿鱼肝脏镉离子的研究

本研究利用大孔阳离子交换树脂脱除鱿鱼肝脏匀浆液中的镉离子。以鱿鱼肝脏匀浆液为原料,镉离子吸附率为评价指标,在试制的离子交换装置基础上研究了大孔强酸性阳离子交换树脂对肝脏匀浆液中镉离子吸附的效果。结果表明,镉离子吸附率随吸附交换时间的增加而升高,当吸附时间为210 min时,离子交换达到平衡状态;降低匀浆液p H,有利于离子交换反应的进行,当p H3.0时,吸附效果较好;树脂用量的增加会提高镉离子的吸附率;镉离子的吸附率在料液比1∶10~3∶10先升高后降低;在25~50℃范围内,升高温度可加快离子交换反应速率。即当树脂用量为20.0 g/L,料液比1∶5,p H3.0,温度为25℃条件下,吸附达平衡状态时,镉离子吸附率可达94.34%。     

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.