亚麻纤维的选择性氧化

采用高碘酸钠对亚麻纤维进行选择性氧化,可使纤维素链单元的2个仲羟基氧化成醛基,红外光谱图证实了活性醛基的生成。在高碘酸钠选择性氧化纤维素过程中,影响氧化程度的因素主要有高碘酸钠质量浓度、氧化时间等。研究了氧化时间和高碘酸钠质量浓度对氧化亚麻纤维醛基含量、失重率和力学性能的影响。结果表明:增加高碘酸钠质量浓度、延长氧化时间,亚麻纤维中的醛基含量增加,但亚麻纤维的失重率增加。随着氧化程度的加深,亚麻纤维的断裂强度逐渐降低。     

高碘酸钠氧化竹原纤维对失重率与强力损失率的影响

竹原纤维是从竹材中直接提取的一种新型天然纤维素纤维,为进一步拓宽竹原纤维的应用领域,采用高碘酸钠为氧化剂,对竹原纤维进行选择性氧化,可反应生成活性基团醛基,有利于对竹原纤维的进一步功能化改性。进一步对氧化后的竹原纤维失重率与强力损失率进行了测试与分析。结果表明:随着高碘酸钠质量浓度的增加和氧化时间的延长,竹原纤维氧化程度提高,纤维降解程度加深,失重率增大,强力损失率增加。在反复实验的基础上对氧化工艺条件进行了优化,以尽可能减小氧化竹原纤维的失重率及强力损失率。     

稻秸秆纤维的高碘酸钠选择性氧化

用碱煮法从稻秸秆中提取纤维,用高碘酸钠对提取的纤维进行选择性氧化,得到二醛基氧化纤维素。研究了氧化剂质量浓度、氧化温度和氧化时间对氧化纤维素的醛基含量和失重率的影响。结果表明,随着氧化剂质量浓度的增加、氧化温度的升高和氧化时间的延长,氧化纤维素的失重率逐渐增大,醛基含量先上升后下降。通过正交试验得出优化的氧化工艺:氧化剂质量浓度15g/L、氧化温度50℃、氧化时间3h。在此工艺下,氧化稻秸秆纤维素的失重率为12.2%,醛基含量为0.590 8mmol/g。     

高碘酸钠选择性氧化棉纤维工艺探讨

为了确定较优的高碘酸钠选择性氧化棉纤维的工艺,选择高碘酸钠用量、氧化时间和氧化温度进行正交试验,综合考虑棉纤维的醛基含量和强力损失率,选取适宜的氧化工艺为:高碘酸钠用量1.5 g/L,40℃氧化2 h.     

亚麻短纤维的选择性氧化及可纺性研究

采用高碘酸钠对亚麻短纤维进行选择性氧化,探讨了高碘酸钠用量和反应时间对醛基含量、断裂强度、失重率和分裂度的影响。结果表明:高碘酸钠的最佳用量为6~7 g/L,最佳反应时间为50~55 min,此时的亚麻短纤维各项性能指标满足可纺性要求。     

丝胶蛋白处理氧化亚麻纤维的工艺研究

采用高碘酸钠对亚麻纤维进行选择性氧化生成醛基,再利用丝胶蛋白溶液对氧化亚麻纤维进行改性接枝加工,研究了不同处理条件对丝胶处理氧化亚麻纱线的增重率、断裂强度和断裂伸长率的影响.结果表明,不同处理条件对氧化亚麻纤维的增重率有一定的影响,但氧化亚麻纤维经丝胶蛋白溶液处理后的断裂强度和断裂伸长率基本不变.     

高碘酸钠氧化对废棉纤维的苯胺吸附性能影响

以废棉纤维为原料,高碘酸钠进行选择性氧化制备二醛基棉纤维。通过傅里叶红外光谱进行分析,结果表明,棉纤维经高碘酸钠氧化后产生醛基,可与苯胺的胺基形成C N席夫碱双键,使氧化棉纤维对苯胺分子具有良好的吸附性能。考察了氧化过程中各因素对氧化棉纤维醛基量以及苯胺吸附率的影响,确定了废棉纤维的较优氧化工艺为:高碘酸钠6 g/L,氧化温度50℃,氧化时间2 h。制得的氧化棉纤维苯胺吸附率达到96%以上。     

亚麻纤维的改性及染色性能的研究

以亚硫酸氢钠溶液对经高碘酸钠氧化处理的亚麻纤维进行磺化改性．并采用阳离子染料进行染色。考查了氧化条件对织物醛基含量和断裂强力的影响：分析了亚硫酸氢钠质量浓度、处理时间、反应温度等因素对磺化效果的影响：并借助红外光谱对氧化亚麻织物与磺化亚麻纤维进行表征。通过对磺化亚麻织物染色性能的研究．     

亚麻纤维的改性及染色性能的研究

以亚硫酸氢钠溶液对经高碘酸钠氧化处理的亚麻纤维进行磺化改性,并采用阳离子染料进行染色.考查了氧化条件对织物醛基含量和断裂强力的影响;分析了亚硫酸氢钠质量浓度、处理时间、反应温度等因素对磺化效果的影响;并借助红外光谱对氧化亚麻织物与磺化亚麻纤维进行表征.通过对磺化亚麻织物染色性能的研究,不但确定了亚麻织物氧化和磺化的最佳工艺,而且用阳离子染料对磺化亚麻织物进行染色,上染百分率较高、染色牢度良好、匀染性和染透性好.     

选择性氧化亚麻纤维的结构研究

本文采用高碘酸钠对亚麻纤维进行选择性氧化,研究了氧化后亚麻纤维的结构。探讨了亚麻纤维大分子上的羟基被氧化成醛基的过程,及其功能化改性特点。     

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.