用胶体滴定法测定阳离子淀粉取代度

采用胶体滴定法测定阳离子淀粉取代度。研究表明，胶体滴定法测定阳离子淀粉取代度操作简便、快速、测量结果准确、重现性好，是一种新型的测定阳离子淀粉取代度的方法。     

阳离子淀粉含氮量的测定研究

用凯氏定氮法测定阳离子淀粉的含氮量,参照国标ＧＢ１２０９１－８９,适当提高裂解样品时催化剂中硫酸铜的比率,增加定氮蒸馏时馏出液体积,测定操作可在３．５ｈ内完成。测定误差〈１％。相对偏差〈０．１％。     

阳离子淀粉作为表面施胶剂的研究

本文的研究目的是为了满足市场对增加纸张内部和表面强度,改善印刷性能和提高纸张强度的需求,采用将木薯淀粉阳离子化原纸进行表面施胶,然后测定纸张性能,探讨阳离子淀粉作为表面施胶剂的最佳应用条件。本文探讨了阳离子淀粉用作纸张表面施胶剂的作用机理,初步研究了制备阳离子淀粉的最优化条件,不同取代度的阳离子淀粉作为表面施胶剂的应用效果。通过对纸张性能（抗张强度、环压强度、吸水性）的测定,找出阳离子淀粉应用的优点。实验结果表明制备阳离子淀粉的最优化条件为木薯淀粉用量为50g,阳离子醚化剂用量为3.008g,n（NaOH）：n（CTA）=1.2：1,反应时间为2h,反应温度为40℃;阳离子淀粉作为表面施胶剂的最佳取代度和固含量分别为0.056和40%。     

淀粉在涂布白卡纸中的应用

在涂布白卡纸生产过程中,淀粉按不同的用途可分为浆内添加阳离子淀粉、抄纸网部喷淋淀粉、烘干部纸板表面施胶淀粉、涂料中作为辅助胶粘剂、保水剂的改性淀粉。1 浆内添加阳离子淀粉浆内添加阳离子淀粉是中性施胶剂ASA或AKD和填料CaCO3的配套助剂。在中性施胶系统中,阳离子淀粉通过形成氢键的能力及其较高的分子质量来提高纤维间结合的能力。另外,阳离子淀粉具有阳电荷、密度强、取代度（DS）较高的特点（取代度＝含氮量／系数K）,它有助于胶料粒子通过静电留着在纤维上,减少细小纤维和碱性填料的流失。阳离子能增进纤维间的结合…     

阳离子淀粉糊液粘度测定影响因素探讨

探讨了搅拌速度、升温时间、淀粉乳加入量等因素对阳离子淀粉糊液粘度测定值的影响,指出提高测定结果重现性的统一操作条件,从而进一步规范阳离子淀粉糊液粘度测定的方法。     

两种方法测定板栗直链淀粉含量的比较

比较碘比色法和碘电位滴定方法测定安徽大红袍和蜜蜂球两种板栗直链淀粉的含量,结果表明:两种方法测得的大红袍板栗直链淀粉含量均高于蜜蜂球板栗,碘比色法测得两种板栗直链淀粉的含量均高于碘电位滴定法.两种测定方法操作均快速简便,但与传统碘比色法相比,碘电位滴定法标准工作曲线采用多个函数拟合的方法绘制而成,直线回归方程相关系数更趋近于1,测得结果的稳定性、重复性较好.是测定板栗直链淀粉含量的一种科学合理有效的新方法.     

影响纤维吸附阳离子淀粉颗粒因素的探讨

利用分光光度计测定纤维对阳离子淀粉颗粒的吸附量,通过改变浆种,添加填料或硫酸铝以及改变其添加顺序等,研究其对纤维吸附阳离子淀粉的影响,目的在于提高阳离子淀粉在湿部的留着率.研究发现:浆料中细小组分含量高;采用先添加硫酸铝后添加阳离子淀粉;先添加阳离子淀粉后添加填料能提高纤维对阳离子淀粉的吸附效率,减少其流失.     

阳离子淀粉／胶体二氧化硅二元助留体系的研究

本文主要对阳离子淀粉／胶体二氧化硅二元助留体系的应用进行了研究。初步研究了阳离子淀粉的用量,胶体二氧化硅的用量,阳离子淀粉、胶体二氧化硅与浆料的接触混合时间、pH值以及实验用水硬度对阳离子淀粉／胶体二氧化硅体系应用效果的影响。通过对浆料留着率的测定,寻找阳离子淀粉／胶体二氧化硅微粒助留体系应用的最佳条件,确定了方案的优化条件,研究表明：在此实验中,阳离子淀粉用量为1％,胶体二氧化硅用量为0．2％,阳离子淀粉、胶体二氧化硅与浆料接触时间分别为60s和30s,混合浆料的pH值为9,实验室用水的Ca2＋含量为200mg／L时的浆料留着率达到最大。     

两种淀粉磷酸酯取代度分析方法的研究

分光光度计法和电位滴定法是测定淀粉磷酸酯取代度的常用方法。实验表明，分光光度计法在数据精密度和重现性方面优于电位滴定法，可同时测多种未知样品，且操作方便，结果准确。     

高温流化处理后大米成分的变化

高温流化是一种新型的原料处理方法，它是利用高温气流(300℃)对大米进行流化处理，可以在极短时间内使淀粉糊化。该文对高温流化大米、蒸煮大米和未处理的原料大米就水分含量、糊化率、淀粉含量、脂肪含量、含氮量5个方面进行了对比测定。     

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.