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。     

肉类加工废水中蛋白质的回收试验

研究了不同絮凝剂回收肉类加工废水蛋白质工艺,实验表明,聚合硫酸铁最优絮凝工艺条件为絮凝荆聚合硫酸铁用量0.3g/L,絮凝时间为35 min,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,聚合硫酸铁是肉类加工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%。     

复合絮凝剂处理酱油废水的试验研究

采用一种阳离子聚丙烯酰胺与聚合氯化铝复合的絮凝剂对酱油废水进行处理,针对反应物配比、pH值、絮凝温度、对复合絮凝剂合成絮凝的影响进行研究。结果表明,配比为5：1,pH值为7,絮凝温度为20℃,对酱油废水COD的去除率可达到80％,取得一定的效果。絮凝对比实验表明：复合絮凝剂的pH值作用范围宽,受温度的影响小,神：唆水处理中投加量少,COD去除能力优于PAC和PAM。     

PAFC与PAM复合絮凝剂处理泡菜废水

采用絮凝法对泡菜废水进行了絮凝烧杯试验,讨论了絮凝剂的选择、PAFC与PAM的不同用量、pH值以及温度对絮凝效果的影响,确定了絮凝剂处理废水的较佳絮凝条件。研究结果表明,PAFC用量90 mg/L,PAM用量60 mg/L,pH值为7,温度为35℃,在此条件下,泡菜废水处理率为:COD、NH3-N、TP去除率分别为83.9%、47%、92.5%。     

阳离子角蛋白与聚硫酸铝配合物絮凝剂的制备及其应用

制得了新型无机一有机配合物絮凝剂,并运用其对皮革染色加脂废水进行絮凝预处理,优化皮革综合废水出水水质。利用傅里叶变换红外光谱仪（FT—IR）对絮凝剂进行结构表征,再对其进行热重（TG）和差示扫描量热法（DSC）测试分析,并分别探讨了不同絮凝剂加入量、pH、絮凝时间、温度对染色加脂废水絮凝效果的影响。试验表明：新合成的絮凝剂在絮疑剂加入2．20g/L、pH=4．0、絮凝时间2．0h、温度25～35℃条件下对COD、悬浮物、色度、总固含量的去除率分别为87．07％、96．56％、99．30％、98．06％,此絮凝剂对皮革染色加脂废水有良好的处理效果。     

制革湿整饰废水的微电解-Fenton氧化联合预处理工艺研究北大核心

针对制革染整废水中含铬和可生化降解性差的问题,研究了碱沉淀除铬与铁碳微电解-Fenton氧化组合的废水预处理工艺,并对工艺条件进行了优化。结果表明：碱沉淀除铬的最佳pH值为8．5,铬去除率大于99％;铁碳微电解-Fenton氧化联合工艺的最佳工艺条件为：两级微电解反应初始pH值2．5,曝气量2L／min,每级反应时间为45min;Fenton氧化反应初始pH值为3．0,双氧水的浓度为5mL／L,反应时间为90min;Fenton氧化反应后调水样pH值为8．0-8．5进行絮凝沉淀。预处理后,废水中的COD去除率达73％,BOD／COD值由0．11提高到0．48,明显提高了废水的可生物降解性。     

絮凝-Fenton氧化处理E段漂白废水的研究

采用絮凝-Fenton氧化处理E段漂白废水。通过正交实验确定了最佳操作参数。Al2（SO4）5-Fen％on氧化配合处理E段漂白废水的最佳操作条件为：Al2（SO4）3用量0．6g／L,氧化反应的pH值为5,H2O2用量1．Og／L,FeSO4用量0．8g／L,在此条件下废水COD的去除率可达90．64％。CPAM-Fenton氧化配合处理E段漂白废水的最佳操作条件为：CPAM用量0．8mg／L,氧化反应pH值6,H202用量1．5g／L,FeSO4用量1．2g／L,在此条件下废水COD的去除率可达82．43％。     

聚丙烯酰胺在工业废水处理中的应用

采用聚丙烯酰胺絮凝剂对某工厂的工业废水进行处理,探讨了投药量、溶液pH值、搅拌时间、反应温度对废水处理的影响,找出了最佳处理条件。结果表明,采用聚丙烯酰胺絮凝剂对工业废水有很好的絮凝效果,最佳条件为:聚丙烯酰胺用量为5mg/L、pH值为8.00、搅拌时间为3min、絮凝温度为40℃。     

酶高温轧蒸退浆工艺

对棉织物的酶高温轧蒸工艺进行研究，讨论了酶浓度、轧余率、轧酶温度、酶液pH值和汽蒸时间等因素对退浆效果的影响，初步确定淀粉酶退浆工艺为：淀粉酶L401．5-2g／L，轧余率100％～110％，室温轧酶（轧前先浸轧60℃热水），酶液pH值约6．5，汽蒸时间15min，汽蒸温度100—102℃。比较碱轧蒸退浆工艺发现，酶退浆工艺退浆率较高，可达7级以上，但毛效、润湿性和白度稍低。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

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.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

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.