鸡卵黄抗体(IgY)的制备工艺研究

对鸡卵黄抗体(简称IgY)的制备工艺进行研究。通过低温乙醇沉淀、DEAE葡萄糖凝胶A-50离子交换层析、Tris-HCl缓冲液洗脱及Sephadex G200凝胶过滤等逐步纯化免疫球蛋白。研究卵黄稀释倍数、pH值、乙醇添加量以及盐浓度对纯化效果的影响。分离纯化后所得的提取物经检测IgY纯度可达98%。用大肠杆菌(E.coli)对其活性进行测定,效果良好,此方法能很好保持免疫球蛋白的活性。     

鸡卵黄免疫球蛋白(IgY)分离纯化的研究

对鸡卵黄免疫球蛋白(IgY)的分离纯化进行了研究.工艺流程为:卵黄→8倍水稀释并搅拌10 min→用HCl调Ph至5.2后在4 ℃静置2 h去沉淀→在上清夜中加入95 %冰乙醇(-20 ℃)使终浓度为60 %(v/v)→4 ℃搅拌20 min后离心(22000 r/min,4 ℃,25 min)→收集沉淀并加入0.028 mol/L NaCl溶液在4 ℃下过滤除去脂蛋白沉淀→收集的滤液用SDS-PAGE法进行纯化得纯度为98 %的1gY.用大肠杆菌(E.coli)对其活性进行测定,效果良好,此方法能保持免疫球蛋白的活性.     

冰乙醇分级离心法分离纯化鸡卵黄免疫球蛋白(IgY)的研究

采用冰乙醇分级离心法提取鸡卵黄免疫球蛋白 (Immunoglobulin of egg yolk,IgY).通过低温乙醇沉淀、DEAE 葡萄糖凝胶 A-50 离子交换层析、Tris-HCl 缓冲液洗脱及 Sephadex G200 凝胶过滤等逐步纯化免疫球蛋白.研究卵黄稀释倍数、pH 值、乙醇添加量以及盐浓度对纯化效果的影响.分离纯化后所得的提取物经检测 IgY 纯度可达98%,且很好地保持了免疫球蛋白的活性.     

卵黄免疫球蛋白的分离提取与鉴定

对氯仿法、辛酸法、水稀释法、水-辛酸法分离卵黄免疫球蛋白(IgY)进行了比较,结果表明:水-辛酸法在9倍稀释度、pH5.3、辛酸加量1%条件下,可获得较好效果,进一步用硫酸铵沉淀脱盐后,提取率达93.4%,产率达4.67mg/mL卵黄,纯度达85%。     

抗变链球菌鸡卵黄免疫球蛋白(IgY)的制备及活性检测

以远缘链球菌(S.sorbrinus 6715血清型g)免疫产卵母鸡,应用酶联免疫吸附测定法(ELISA)测定鸡卵黄中免疫球蛋白(Immunoglobulin of Yolk,IgY)的活性,研究鸡免疫应答并制备出高免抗-S.sorbrinus IgY.结果显示以109 cfu/只剂量免疫的母鸡,第一次免疫后的第七天卵黄中出现特异性IgY,加强免设后抗体效价上升更快,经ELISA法检测,卵黄中的抗体效价到1384.而冷冻干燥后的IgY,其效价要超过12000.     

绿色高效连续分离技术制备蛋黄中活性蛋白质和磷脂

为了实现蛋黄功能性成分的充分利用，采用绿色溶剂从新鲜蛋黄中高效连续分离具有生物活性的卵黄免疫球蛋白（immunoglobulin Y, IgY）、卵黄高磷蛋白（phosvitin, PV）和磷脂（phospholipids, PL）。首先采用水稀释法（稀释倍数为1:10）分离水溶性组分与脂蛋白，通过35%饱和(NH₄)₂SO₄和0.5% NaCl（w/v）对上清液进行盐析并用8% PEG 6000纯化IgY。脂质组分中的PV在pH5.0，90 ℃条件下的NaCl溶液（w/v）中进一步纯化。采用乙醇/乙酸乙酯比例为1:2（v/v）提取蛋黄中全部脂类，进一步采用乙酸乙酯在0 ℃下提纯蛋黄总脂中的PL。经脱盐、冷冻干燥后，IgY、PV和PL的纯度分别为97.38%、78.63%和85.94%。IgY和PV的得率分别为6.15、10.15 mg/mL。蛋黄总脂中PL的含量为35.18%。因其良好的多不饱和脂肪酸/饱和脂肪酸比率（0.70）和相对较低的n-6/n-3比率（5.37），该PL产品可应用于食品加工中。本方法简便、环保并且高效，可从蛋黄中依次分离出高纯度IgY、PV和PL，并为蛋黄的综合利用提供技术支持。     

免疫卵黄抗体提取工艺的优化

以水稀释法为基础,结合PEG6000沉淀法对卵黄中IgY进行分离提取。探讨稀释倍数、溶液pH值、静置时间、PEG6000浓度等因素对IgY提取率的影响,并通过正交试验对分离条件进行优化。通过单因素和正交试验得到最佳分离条件为稀释8倍、溶液pH值5.2、静置时间8h、PEG6000浓度8%,该条件下IgY提取率达到13.69mg/g;各因素对IgY提取率的影响顺序为PEG6000浓度>稀释倍数>静置时间>溶液pH。     

单增李斯特菌(Listeria monocytogens)鸡卵黄抗体的制备及其抑菌活性研究

以单增李斯特菌为抗原免疫产蛋母鸡,比较了不同方法对于鸡卵黄中单增李斯特菌抗体(IgY)的分离效果,研究确定了所得IgY的主要理化性质及其对于单增李斯特菌的体外抑菌效果。研究结果表明,采用硫酸铵盐析法可以取得较好的提取纯化效果,提取液中的单增李斯特菌抗体效价可以达到1∶10 000以上,且蛋白组分较为单一。IgY具有较好的理化稳定性,pH3～9范围内均可保持70%以上的免疫活性,经60℃、4 h处理后仍保持约67%的免疫活性。体外抑菌实验显示,液态培养8 h、固态培养24 h后,该抗体能够对于单增李斯特菌的生长产生显著的抑制率效应;这表明其有望作为新型天然抗菌剂用于生物体及动物性食品中单增李斯特菌的预防和控制。     

低温乙醇除脂法纯化鸡卵黄中免疫球蛋白

采用低温乙醇除脂法提取鸡卵黄免疫球蛋白 (immunoglobulinyolk,IgY)。通过低温乙醇沉淀、透析和葡聚糖凝胶等不同方法逐步纯化免疫球蛋白。研究了卵黄稀释倍数、乙醇浓度、NaCl浓度以及离心转速对纯化效果的影响。分离纯化后所得的冷冻干燥制品 ,经SDS PAGE和抑菌试验检测可知 :可溶性蛋白质得率为每毫升蛋黄 1 2 6mg ,可溶性蛋白质含量占总蛋白质量的 97% ,且保持了免疫球蛋白的活性     

卵黄抗体咀嚼片配方优化及生物稳定性研究

以卵黄抗体(immunoglobulin of yolk,IgY)、脱脂奶粉和硬脂酸镁等为原辅料混合直接压制成卵黄抗体咀嚼片。以硬度和感官评分为指标,通过单因素和正交试验确定IgY咀嚼片压制配方;体外探讨不同温度、pH、胃蛋白酶和胰蛋白酶处理对咀嚼片中IgY效价的影响并模拟胃肠道消化;通过灌喂小鼠,探究IgY咀嚼片的体内消化代谢。IgY咀嚼片最佳配方为脱脂奶粉45%、硬脂酸镁1.9%、矫味剂45%、微晶纤维素6.1%。IgY咀嚼片在60℃温度处理1 h,IgY咀嚼片抗体效价为阴性。在pH 4～8之间IgY咀嚼片效价稳定;在pH 1.2条件下处理3 h,抗体失活率53.63%;胃蛋白酶消化2 h,抗体失活率19%;胰蛋白酶消化3 h,抗体失活率91.03%。体外模拟胃肠道消化5 h,IgY咀嚼片无抗体活性。小鼠体内消化代谢高中剂量组,灌喂0.5～1 h,在胃、十二指肠内检测抗体效价阳性;灌喂3 h,在空肠中检测抗体效价阳性;灌喂6 h,在回肠中检测抗体效价阳性;灌喂12 h,在消化道内均检测抗体效价阴性。IgY咀嚼片适口性好,可以在消化道内保存一定的生物稳定性,为IgY的使用提供了新的思...     

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.     

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.     

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.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

Analysis on Economic Indicators from 62 Enterprises in Printing Machinery Industry in Q1 2014

Operation of printing machine industry was still unsatisfactory in the first quarter of 2014.Analysis on operation of printing machine industry.a.Market demand was not strong;sales of product undulated and declined.According to the statistics,the total industrial output value fell by 19.28% in the first quarter of 2014 than the average quarter value in 2013; industrial added value decreased by 4.16%; sales revenue dropped by 22.83%. h. Business operation of enterprises was in poor condition. c. R＆D of new products is an important transformation guarantee for enterprises. d. To take self explore new ways upgrading advantages,and explore new ways.