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.     

赤砂糖回溶糖浆两步法澄清脱色工艺的研究

壳聚糖和氢氧化镁的絮凝最佳pH值差异较大,复合或同时使用效果较差。因此,采用两步法工艺,分别使用壳聚糖和氢氧化镁2种助剂对赤砂糖回溶糖浆进行澄清脱色,获得了较好的澄清脱色效果。试验中,首先用壳聚糖进行第一步絮凝脱色,絮凝迅速,絮体大而密实,易于过滤;然后往滤液中加入镁盐,同时使用CaO作为碱化剂进行第二步絮凝。运用单因素和多因素正交试验探讨了pH值、壳聚糖用量以及镁盐用量等因素对澄清脱色效果的影响,结果表明,最佳工艺条件为:壳聚糖量0.2g/L、镁盐量5g/L、壳聚糖絮凝pH值为4.8、氢氧化镁混凝的pH值为11.2,在最佳的工艺条件下,脱色率达到87.7%。     

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。     

基于壳聚糖和γ-聚谷氨酸的协同絮凝法对赤砂糖回溶糖浆的澄清脱色研究

基于壳聚糖和γ-聚谷氨酸的协同絮凝对赤砂糖回溶糖浆进行澄清脱色处理.实验中,通过先后加入壳聚糖、γ-聚谷氨酸实现协同絮凝,应用于赤砂糖回溶糖浆的澄清脱色,获得了理想的效果.运用单因素和多因素正交实验探讨了壳聚糖用量、pH、γ-聚谷氨酸用量、反应温度等因素对澄清脱色效果的影响,结果表明:壳聚糖和γ-聚谷氨酸对糖浆澄清脱色的最佳工艺条件为:壳聚糖量0.5g/L;γ-聚谷氨酸量0.06g/L;pH5.0;反应温度20℃.在最佳工艺条件下,脱色率达到66.5％.     

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。     

壳聚糖在小球藻采收中的应用

以壳聚糖为絮凝剂采用絮凝法采收小球藻的细胞生物量 ,系统研究了壳聚糖用量、pH值、藻液浓度以及搅拌速度等因素对絮凝效果的影响。结果表明 ,用壳聚糖絮凝采收小球藻的生物量 ,不仅用量少、效率高 ,并且安全无毒 ,可简化分离工艺和降低生产成本     

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。     

基于壳聚糖和γ-聚谷氨酸的协同絮凝法对赤砂糖回溶糖浆的澄清脱色研究

基于壳聚糖和γ-聚谷氨酸的协同絮凝对赤砂糖回溶糖浆进行澄清脱色处理。实验中,通过先后加入壳聚糖、γ-聚谷氨酸实现协同絮凝,应用于赤砂糖回溶糖浆的澄清脱色,获得了理想的效果。运用单因素和多因素正交实验探讨了壳聚糖用量、pH、γ-聚谷氨酸用量、反应温度等因素对澄清脱色效果的影响,结果表明:壳聚糖和γ-聚谷氨酸对糖浆澄清脱色的最佳工艺条件为:壳聚糖量0.5g/L;γ-聚谷氨酸量0.06g/L;pH5.0;反应温度20℃。在最佳工艺条件下,脱色率达到66.5%。      

苹果梨酒澄清剂及澄清条件的研究

用壳聚糖、皂土和明胶对苹果梨发酵酒的澄清效果进行研究。结果表明,壳聚糖、皂土澄清效果优于明胶,壳聚糖澄清效果最佳,但澄清周期最长。对壳聚糖用量、温度和pH值进行正交优化试验,结果显示,壳聚糖用量为0.06%、澄清温度为25℃、pH值为4.0时苹果梨发酵酒的澄清效果最好。     

壳聚糖-聚合氯化铝复合絮凝剂对糖浆脱色的研究

研究了壳聚糖(CTS)-聚合氯化铝(PAC)复合絮凝剂对赤砂糖回溶糖浆脱色的效果。考察CTS-PAC复合絮凝剂的不同配比、不同用量、不同pH、不同絮凝温度、不同絮凝时间等因素,通过正交表L25(55)安排实验,得到最佳工艺条件为:絮凝剂用量为300mg/kg、PAC∶CTS配比为2∶4、pH为6.2、温度为75℃、时间为8min。     

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.     

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.     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the