牦牛血中免疫球蛋白热变性动力学的研究

研究了免疫球蛋白的热稳定性及热变性动力学,结果表明:牦牛血IgG的热变性属于0级反应。在65、70、75、80、85℃条件下,IgG变性的D值分别为722.41、311.65、17.8、5.24、2.73、1.89min,在此温度范围内IgG变性的Z值为7.9℃,表观活化能为271.25kJ/mol。依据IgG热变性动力学方程计算,63℃30min杀菌,IgG变性率为2.79%;在72℃30s,75℃15s及85℃5s条件下杀菌,IgG变性率分别为0.58%、0.66%和3.03%,UHT处理(120℃4s)IgG活性全部丧失。这些结果说明,LTLT和HTST巴氏杀菌对牦牛血中IgG活性影响较小,但不可采用UHT工艺。     

免疫乳中IgG热变性动力学研究

对免疫乳中IgG的热稳定性及热性动力学进行了研究。结果表明,IgG的热变性属于1.2级反应。在65,70,75及80℃条件下,IgG变性的D值分别为769.23,185.18,21.55和5.09min,在此温度范围内IgG变性的Z值为6.69℃,表观活化能为345.69kJ/moL。依据IgG热变性动力学方程计算,63℃、30min杀菌,IgG变性率为3.94%;在72℃、30s,75℃、15s及85℃、5s条件下杀菌,IgG变性率分别为0.36%、0.52%和5.05%,UHT处理（120℃、0.4s)IgG全部失活。这些结果说明,乳品工业中常用的LTLT和HTST巴氏杀菌对免疫乳中IgG活性影响较小,但不可采用UHT工艺。     

乳铁蛋白热稳定性及热变性动力学的研究

通过对乳铁蛋白在不同温度加热条件下活性残存率的测定，分析了乳铁蛋白的热稳定性及热变性动力学。结果表明，乳铁蛋白的热变性反应级数是1．9。在65，70，75，80，85，90及95℃的加热条件下，Lf变性的D值分别为32．68，26．81，23．98，8．18，6．07，2．90和2．21min，在此温度范围内的Z值为23．1℃，表观活化能Ea=125.07kJ／mol。     

大豆分离蛋白凝胶制备和凝胶质构特性研究

本研究以大豆分离蛋白为原料，考察蛋白质浓度、pH值、加热温度、加热时间对凝胶形成的影响，采用物性仪对不同务件下制备的凝胶的质构特性进行研究，不同评价指标得出的结论不尽相同。通过正交实验得出形成凝胶硬度最大的制备条件为：蛋白浓度12％，pH值6．5，加热温度95℃，加热时间35min；形成凝胶脆性最大的制备凝胶争件为：蛋白浓度12％，pH值7．0，加热温度95℃，加热时间25min；形成凝胶弹性最好的制备凝胶务件为：蛋白浓度12％，pH值7．0，加热温度85℃，加热时间35min；形成凝胶粘附性最大的制备凝胶条件为：蛋白浓度12％，pH值7．0，加热温度95℃，加热时间35min。     

羊初乳免疫球蛋白(IgG)稳定性的研究

研究了酸、碱、糖、加热对羊初乳中免疫球蛋白（IgG）稳定性的影响.结果表明,IgG在pH值为5.0～10.0范围内比较稳定,在pH值为低于5.0条件下,随pH值降低,变性率剧烈上升;在加热或pH2.0的环境下,糖醇化合物对IgG具有保护作用,随着糖类浓度的升高IgG的变性率降低,其中蔗糖、果糖、麦芽糖的效果较好,葡萄糖、乳糖的效果较差;羊初乳中IgG对加热比较敏感,随着加热温度的上升,其变性率增大.于55℃加热30 min,变性率为25.5%;于65℃加热30 min,变性率为38.1%;于75℃加热7 min时,变性率已达100%;于85℃加热2.0 min时变性率也已达100%.     

牛初乳粉中免疫球蛋白热稳定性及热动力学的研究

通过测定牛初乳在不同温度下IgG的活性含量,研究了牛初乳粉中IgG对热的稳定性。利用Arrhenius方程,分析了牛初乳中IgG热变性过程中的热动力参数。研究表明,复原牛初乳IgG在<65℃范围内具有较高的稳定性。热动力学分析表明,复原牛初乳IgG热变性反应级数是1.1,在65,70,75,80,85,90℃的D值分别为188.68,34.36,6.18,3.07,1.80,0.95min,在65~90℃范围内的Z值为11.20℃,表观活化能Ea=216.41kJ/mol。     

牛初乳中IgG抗原决定簇以及蛋白质G结合部位热变性的对比

对比研究热处理（69～81℃）过程中牛初乳IgG分子抗原决定簇部位及其蛋白质G结合部位的变性动力学。利用单向琼脂扩散法（RID）监测IgG分子的热变性状况,其抗原决定簇部位热变性可用反应级数为1.2的方程较好地描述。结果表明,在69,72,77,81℃条件下IgG变性的D值分别为5000,2000,500,270 s,Z值为9.43℃,变性活化能为270.55 kJ/mol;利用蛋白质G亲和色谱法监测IgG分子上蛋白质G结合部位的热变性状况,在反应级数n=1.2,温度在69,72,77,81℃条件下IgG变性的D值分别为14286,3333,625,313 s,Z值为7.25℃,变性活化能为316.42 kJ/mol。所以IgG分子中抗原决定簇部位较之其蛋白质G结合部位更易于受热变性,较之RID,采用蛋白质G亲合色谱法检测牛初乳制品IgG的结果将偏高。     

乳清蛋白组分在脱脂乳和乳清体系中热变性率的比较研究

脱脂乳粉生产过程的预杀菌工艺对乳清蛋白变性有很大影响,乳清蛋白的变性程度主要取决于温度和时间的变化。本文对脱脂乳体系和乳清体系进行55～95℃,1～30 min加热处理,通过反相高效液相色谱(RP-HPLC)检测加热后样品中乳清蛋白主要组分并进行比较分析。结果表明:在脱脂乳体系与乳清体系中,牛血清白蛋白(BSA)变性趋势基本相同,温度达到65℃时变性显著,85～95℃几乎全部变性。α-乳白蛋白(α-La)的变性率在温度低于75℃时变性率差异较小,而在75～95℃的加热范围内变性率区别明显。β-乳球蛋白(β-Lg)在75～85℃加热范围内变性率有明显差异,3种乳清蛋白组分的热变性程度均显示出受热时间和温度的累积效应,最终趋向全部变性。与脱脂乳中蛋白热变性比较表明,酪蛋白对乳清蛋白中牛血清白蛋白的变性影响不大,而在65～95℃间对α-乳白蛋白、β-乳球蛋白的热变性有一定的促进作用。     

油棕榈果球丝烧碱-蒽醌法蒸煮脱木质素机理的研究

对马来西亚的油棕榈果球丝烧碱．蒽醌法蒸煮工艺及其蒸点脱木质素机理进行了研究，结果表明：在所选燕煮工艺范围内，影响油棕榈果球丝烧碱-蒽醌法蒸煮脱木质素率、纸浆得率和黑液残碱的主要因索是蒸煮最高温度，其次为用碱量，影响最小的为保温时间。而其脱木质素可分为初始脱木质索、主要脱术质素和残余脱木质索3个阶段；即蒸煮温度升至100℃时，为初始脱木质素阶段，木质素脱除率2．10％；当蒸煮温度从100℃升至160℃并保温30min，此阶段为主要脱木质素阶段，此阶段脱除81．0％的木质素；当在160℃保温从30min至120min时，属残余脱木质素阶段，此阶段木质素的脱除率为12．1％。     

牦牛乳过氧化物酶体系及其酶热动力学研究

以麦洼牦牛乳为原料,分析了其乳过氧化物酶体系相关成分的浓度,并研究了不同温度下牦牛乳过氧化物酶(LPO)的热稳定性,利用一级反应动力学模型和阿仑尼乌斯方程,分析了牦牛乳中LPO在63～67℃热变性过程中的动力学参数。结果表明,牦牛乳LPO在63℃时具有较高的热稳定性。热动力学分析表明,牦牛乳LPO在63、65和67℃的D值分别为207.43、33.41、13.42min,在63～67℃范围内的Z值和表观活化能(Ea)分别为3.36℃和557.20kJ/mol。     

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.     

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     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press