不同絮凝剂在肠衣废水蛋白质回收中的应用研究

研究了不同絮凝剂回收肠衣废水蛋白质工艺,实验结果表明,聚合硫酸铁最优絮凝工艺条件为絮凝剂聚合硫酸铁用量为0.3g/L,絮凝时间为35min,絮凝pH值为7.0,絮凝温度为30℃。蛋白质回收率达到90.1%,COD去除率达到81.2%;壳聚糖最优絮凝工艺条件为絮凝剂用量为0.3g/L,絮凝时间为35min,絮凝pH值为6.5,絮凝温度为30℃。蛋白质回收率达到83.1%,COD去除率达到76.4%;单从蛋白质去除率和COD去除率出发,聚合硫酸铁是肠衣废水预处理的最佳絮凝剂,但从回收蛋白质再利用角度出发,应选择壳聚糖。     

魔芋絮凝剂处理蛋白废水的研究

本研究以魔芋系列产品为絮凝剂研究了蛋白废水絮凝工艺条件。分别考察了絮凝剂种类、pH值、COD初始值和絮凝剂用量对COD去除率的影响,采用正交试验对絮凝条件进行优化。结果表明:魔芋微粉絮凝效果最佳;pH值对絮凝有极显著影响;COD初始值对絮凝有显著影响;絮凝剂用量宜在3.0g/L以上,在3.5～5.0g/L范围内未见显著差异;絮凝的最适条件是pH4.5,COD初始值6892mg/L以及微粉用量3.5g/L;最适条件下的COD去除率达75.84%。     

壳聚糖改性絮凝剂处理印染废水的研究

研究了用壳聚糖与丙烯酰胺接枝共聚物做为絮凝剂对印染废水的絮凝处理,并与壳聚糖进行了絮凝效果比较,考查了pH值、无机絮凝剂、有机絮凝剂等因素对处理效果的影响。实验结果表明,在pH值5-8,PAC用量500mg/L,壳聚糖改性絮凝剂用量60mg/L时,染料废水的脱色率可达95%以上,COD去除率达76%,其絮凝效果明显好于壳聚糖。     

甲壳素废水中虾青素与蛋白质絮凝工艺条件的研究

对含有虾青素的甲壳素废水的絮凝工艺条件进行了研究。试验结果表明,采用明矾作絮凝剂效果最佳;较佳的絮凝工艺条件为:55℃,水浴20min,pH为6.0,絮凝剂用量为20mg/L;经凯氏定氮测得蛋白质和虾青素混合物的回收率达到89.1%。     

壳聚糖改性絮凝剂在染料废水处理中的应用

采用壳聚糖与有机单体丙烯酰胺接枝共聚制备絮凝剂,并用此絮凝剂对活性染料废水进行混凝处理.考查了无机絮凝剂、有机絮凝剂、废水pH值等因素对处理效果的影响.实验结果表明,在pH值5～9,PAC用量500 mg/L,壳聚糖改性絮凝剂用量6 mg/L时,染料废水的脱色率可达95%以上,COD去除率高于74%.壳聚糖改性絮凝剂处理活性染料废水时,具有原料来源丰富、用量小、使用条件温和、成本较低、絮凝效果显著等优点.     

絮凝微滤组合工艺处理退浆废水

采用絮凝微滤组合工艺处理退浆废水，考察了聚硅酸硫酸铝絮凝剂用量、温度、pH值、搅拌时间对退浆废水处理效果的影响，得出了适宜的絮凝条件：絮凝剂投加量120mL/L，温度30℃，pH值4，搅拌2min。与单一微滤相比，絮凝微滤组合工艺处理退浆废水，COD去除率提高了20％～40％，最终渗透液COD仅为4570mg／L。在80℃，采用5g／L的氢氧化钠和10g／L的硝酸溶液交替清洗2h，陶瓷膜的通量恢复率可达到95％。     

胶原蛋白与PAM絮凝剂处理造纸中段废水的研究

研究了胶原蛋白絮凝剂处理造纸中段废水的工艺条件,探究了絮凝剂加入量、反应时间、反应温度、pH值对COD去除率、SS去除率、色度去除率的影响。实验结果表明:调节废液pH值在6,絮凝剂用量在2 mg/L,温度在40℃,反应时间30min,能够沉降废水中大部分悬浮物质,使废水COD明显降低。其胶原蛋白絮凝剂可达到COD去除率59.41%、SS去除率77.12%、色度去除率86.67%,而PAM在其最佳处理条件去除效果达到COD去除52.22%、SS去除率65.91%、色度去除率67.59%,同时使用胶原蛋白絮凝剂比PAM节省1.2元·t-1纸,可见胶原蛋白絮凝剂较优于PAM。     

壳聚糖絮凝分离豆腐废水蛋白的研究

研究了采用生物絮凝法处理豆腐废水的可行性。探讨了絮凝剂的种类、添加量、废水的前处理、絮凝时间及pH对絮凝效果的影响,并重点比较了复合絮凝剂对废水中蛋白质和低聚糖的絮凝作用。单一絮凝剂试验结果显示壳聚糖的絮凝效果明显优于聚合硫酸铁、聚合三氯化铝、海藻酸钠、聚丙烯酰胺。较优的添加量为0.6~0.8 mg/mL,添加量过高浊度会不降反升。絮凝前废水-18℃冷冻处理有利于蛋白质的分离,絮凝后的沉降是必要的,时间以12 h为宜。复合絮凝剂中所有组合都表现出明显的协同增效作用,尤以0.5mg/mL壳聚糖+0.3mg/mL海藻酸钠效果最佳,pH 4.5条件下絮凝后浊度降低97.8%,原液中蛋白脱除率高达76.842%,而低聚糖(减少6.56%)几乎不受影响,是较为理想的豆腐废水絮凝剂组合。     

壳聚糖絮凝剂在硫酸软骨素废水处理中的应用

硫酸软骨素生产过程中,会产生含有大量有机物的工业废水。本文选用壳聚糖作为絮凝剂,以絮凝剂用量、絮凝温度、絮凝时间、絮凝pH值为因素作正交试验L9(34),通过正交试验来分析影响絮凝效果的主要因素,确定最佳的絮凝工艺条件。实验表明,壳聚糖处理后的COD去除率达65%左右。     

壳聚糖絮凝剂对粉丝废水的絮凝效果研究

研究了壳聚糖为絮凝剂絮凝沉降粉丝浓浆废水的条件及效果。结果表明 ,絮凝沉降速度快 ,COD除去率为 86 % ,蛋白质回收率为 81%。在 p H条件为 6 .5～ 8.5时 ,高浓度较低浓度的壳聚糖絮凝效果好 ,煮沸废水有利于沉降     

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.