Al-Zr-CeO_2固体酸催化剂的制备及其油脂环氧化性能

采用离子交换法和浸渍法制备Al-Zr-CeO_2固体酸催化剂,利用SEM、XPS、XRD、FT-IR和氮气吸附—脱附对固体酸催化剂进行了表征,结果表明:Al_2O_3和ZrO_2负载在CeO_2表面,大大提升了Al-Zr-CeO_2复合催化剂的比表面性能,在高温下仍有较高的比表面积,且催化效果显著。同时以大豆油的环氧化反应为探针反应,考察了煅烧温度、煅烧时间、Al(NO_3)_3/CeO_2的质量比和Zr(NO_3)_4/CeO_2的质量比对催化剂Al-Zr-CeO_2催化活性的影响。催化剂的最佳制备条件为:煅烧温度400℃,煅烧时间2 h,Al(NO_3)_3/CeO_2的质量比为0.2,Zr(NO_3)_4/CeO_2的质量比为0.2。该条件下制备的催化剂,在催化大豆油的环氧化反应时,环氧值可达到5.54%。     

SO2-4 /Al2 O3 催化剂的表征及其在环氧化反应中的催化活性

采用浸渍法制备不同煅烧温度下的固体超强酸SO2-4 /Al2O3。使用傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、氨气程序升温脱附(NH3-TPD)和氮气物理吸附(N2-BET)技术表征了固体超强酸的表面性质、晶形,并将其用于催化蓖麻油环氧化反应。结果表明：在蓖麻油质量20 g、催化剂用量2 g、煅烧温度600 ℃、过氧化氢滴加温度40 ℃、反应温度55 ℃、反应时间8 h的条件下,环氧化蓖麻油的碘值（Ⅰ）为48.4 g/100 g,环氧值可达0.551%;催化剂重复使用4次后,仍表现出较好的催化活性。     

Al-Zr-SiO2固体酸催化大豆油环氧化的研究

以Al-Zr-SiO_2固体酸为催化剂制备环氧大豆油,考察反应时间、催化剂用量、反应温度、n(H_2O_2)∶n(双键)对环氧化反应的影响,并通过响应面试验对环氧化反应工艺条件进行优化。得到环氧化反应最佳工艺参数为,大豆油∶甲酸∶过氧化氢=1∶0.5∶2.5(摩尔比),Al-Zr-SiO_2固体酸催化剂用量为0.8%,反应温度为70℃,反应时间为4 h,在该条件下所得大豆油的环氧值为6.57%。     

SnO2-Al2O3固体酸催化大豆油酯交换制备生物柴油

采用共沉淀法制备SnO2-Al2O3复合固体酸催化剂,用于催化大豆油甲醇解反应,考察催化剂制备条件和酯交换反应条件对大豆油转化率影响。研究结果表明,催化剂最佳制备条件为Sn／A1摩尔比3：1,煅烧温度为923K;催化大豆油酯交换反应醇油摩尔比30：1,催化剂用量3wt．％,反应时间5h,反应温度200℃,此时大豆油转化率最高,为75．05％。当向酯交换反应体系加入一定量游离脂肪酸或水分时,SnO2-Al2O3催化剂催化活性几乎不受影响,且还能同时催化酯化反应;结果还表明,固体酸SnO2-Al2O3具有很好稳定性,可多次重复利用。     

固体酸碱催化餐饮废油脂制备生物柴油

采用固体酸、碱催化餐饮废油脂制备生物柴油.首先用煅烧后的(NH4>)2>SO4>/Al2>O3>催化甲醇和餐饮废油脂中的游离脂肪酸进行预酯化反应,然后再用煅烧后的Na2CO3/Al2O3催化甲醇和餐饮废油脂中的甘油三酯进行酯交换反应.结果表明,经预酯化的餐饮废油脂在以正己烷为溶剂、溶剂用量为1.5 mL/g(oil)、醇油摩尔比为15:1、反应温度为50℃、反应时间为4 h和催化剂用量为8%的最佳工艺条件下进行酯交换反应.反应转酯率为96.85%.     

LiNO_3/ZrO_2催化大豆油酯交换制备生物柴油

以固体碱催化剂LiNO_3/ZrO_2催化大豆油甲醇解反应,探讨催化剂制备条件和反应条件对大豆油转化率影响。实验结果表明:LiNO_3/ZrO_2催化大豆油甲醇解最适制备条件和反应条件是:负载量3 mmol/g,煅烧温度923 K,醇油摩尔比12:1,催化剂用量6.0wt.%,反应时间5 h,最高转化率可达95.24%。     

香料己酸丙酯的非均相催化合成研究

以固体酸Zr(SO4)2/硅藻土为催化剂,通过己酸和正丙醇的酯化反应合成香料己酸丙酯。考察了催化剂Zr(SO4)2/硅藻土的制备条件对其催化性能的影响,得出适宜的制备条件为:催化剂中硫酸锆与硅藻土的质量比例4∶6,焙烧温度350℃,焙烧时间2 h。采用正交实验优化了固体酸Zr(SO4)2/硅藻土催化合成己酸丙酯的工艺条件,得出较佳的催化反应条件为:酸醇比1∶1.75,催化剂用量0.5 g,带水剂用量3m L,反应时间1.5 h。在此条件下,己酸丙酯的酯化率可达99.2%。     

钙矾二元复合金属氧化物催化大豆油酯交换研究

实验制备CaO/V2O5固体碱催化剂,研究钙钒摩尔比和煅烧温度对催化剂活性影响;结果表明,最适制备催化剂条件为:钙矾摩尔比3∶1、煅烧温度823 K。考察该催化剂对油脂酯交换反应活性,CaO/V2O5催化大豆油酯交换最适反应条件为:醇油摩尔比15∶1、催化剂用量6.2 wt.%、反应时间4 h,大豆油转化率达80%;该催化剂重复使用5次后,活性并没明显降低,游离脂肪酸和水分含量对该催化剂活性影响很小。     

固体酸碱两步法催化麻疯籽油制备生物柴油反应过程的研究

以麻疯籽油为原料,对固体酸SiO_2/Zr(SO_4)_2-Ti(SO_4)_2、固体碱K_2CO_3/MgO-Al_2O_3两步法催化麻疯籽油制备生物柴油的反应过程进行研究,即第一步以固体酸为催化剂,催化麻疯籽油中的游离脂肪酸和甲醇预酯化,第二步以固体碱为催化剂,催化麻疯籽油与甲醇进行醇解反应。利用单因素实验及正交实验对固体酸碱两步法催化麻疯籽油制备生物柴油的反应过程进行优化。研究结果表明,固体酸催化预酯化的最佳条件为:催化剂用量2%,醇油摩尔比12:1,反应温度75℃,反应时间2 h,在此条件下酸值由10.47 mgKOH/g降为0.70 mg KOH/g。碱催化醇解反应的最佳条件为:催化剂用量为2%,醇油摩尔比为12:1,反应温度为65℃,反应时间2 h,醇解转化率稳定在95%左右。固体酸—碱两步法适用于催化麻疯籽油制备生物柴油,实验结果为实现麻疯籽油生物柴油的工业化生产奠定了一定的理论基础。     

豆渣基固体酸的制备及催化大豆油的环氧化

为了促进豆渣的资源化利用,以豆渣为原料,通过同步炭化磺化法制备豆渣基固体酸催化剂,并将其应用于催化合成环氧大豆油,考察了磺化剂种类、磺化剂用量、磺化温度及磺化时间对豆渣基固体酸结构及催化性能的影响。结果表明：以硫酸为磺化剂,在硫酸与豆渣质量比2∶1、磺化温度190℃和磺化时间10 h的条件下,制备的豆渣基固体酸BD-1-2对大豆油的环氧化反应表现出较好的催化性能,环氧大豆油的环氧值达到6.30%;BD-1-2在200℃以内可保持热力学性质稳定; 扫描电镜结果显示,BD-1-2结构中包含表面光滑的微球结构以及表面粗糙的无规则片状结构;BD-1-2经4次使用后仍保持较好的催化性能。综上,所制备的BD-1-2可应用于环氧大豆油的高效合成。     

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.