鲢鱼降血压肽的酶解条件

以鲢鱼蛋白为原料,采用5种不同复合蛋白酶(P1,P2,P3,P4,P5)进行酶解,综合研究了复合生物酶酶量、酶解时间、pH、酶解温度等对鲢鱼蛋白酶解降血压肽ACE活性抑制效果的影响。结果表明,复合酶P1酶解降血压肽对ACE抑制率经体外检测为88.08%,具有最佳的酶解效果。对应最佳条件为:酶量25 IU/mL,酶解时间2 h,pH7.0,酶解温度60℃。     

罗非鱼鱼鳞胶制备降血压胶原肽的工艺及酶解物活性

以罗非鱼鱼鳞胶为原料,制备对血管紧张素转换酶(ACE)有抑制活性的降血压肽。以水解度(DH)及ACE抑制率为指标,筛选水解鱼鳞胶的最适酶种,并对其水解工艺条件进行优化;采用超滤技术对所制备的降血压肽进行分离纯化,比较不同组分的ACE抑制率,测定高ACE抑制率组分的氨基酸组成,并运用MALDI-TOF-MS法分析其分子质量分布。结果表明,复合蛋白酶是水解鱼鳞胶最适酶种,在50℃、pH7.5、料液质量体积比1∶5、酶与底物质量比(mE/mS)1.5%条件下,酶解6 h,酶解液的ACE抑制作用最强,其水解度DH 73%,ACE的抑制率76.15%。酶解液经超滤分离所获得的分子质量小于2 000 u的组分对ACE抑制率最高,达83.15%;该组分的氨基酸主要含有Gly和Pro,含量分别为22.04%和11.40%;该组分分子质量范围为1 300~2 000 u。     

木瓜蛋白酶在制取青鳞鱼可溶性蛋白中的应用

研究了木瓜蛋白酶的酶解温度，酶浓度，酶解时间，加水量，pH值对青鳞鱼可溶性蛋白得率的影响，探讨了α－氨态氮含量与青鳞鱼与可溶性蛋白得率的关系。结果表明：温度小于50℃，随着酶解温度的提高，酶浓度的增加，酶解时间的延长青鳞鱼可溶性蛋白得率及α－氨态氮的含量均增加，α＝氨态氮含量增加比可溶性蛋白得率的增加明显；加水量的增加，可溶性蛋白得率增加；pH值对水解效果及可溶性蛋白得率影响不大。综合考虑，最佳水解条件为：温度50℃，酶浓度为1500u/g，酶解时间80min,m原料：m水＝1：2，pH6.8。酶解所得可溶性蛋白经氨基酸分析仪检测,其氨基酸总量为49.47mg/mL，必需氨基酸占氨基酸总量的41．0％，游离氨基酸含量为6.3mg/mL，肽含量为87．2％。     

木瓜蛋白酶在制取青鳞鱼可溶性蛋白中的应用

研究了木瓜蛋白酶的酶解温度、酶浓度、酶解时间、加水量、pH值对青鳞鱼可溶性蛋白得率的影响 ,探讨了α 氨态氮含量与青鳞鱼可溶性蛋白得率的关系。结果表明 :温度小于 5 0℃ ,随着酶解温度的提高、酶浓度的增加、酶解时间的延长青鳞鱼可溶性蛋白得率及α 氨态氮的含量均增加 ,α 氨态氮含量增加比可溶性蛋白得率的增加明显 ;加水量的增加 ,可溶性蛋白得率增加 ;pH值对水解效果及可溶性蛋白得率影响不大。综合考虑 ,最佳水解条件为 :温度 5 0℃ ,酶浓度为 1 5 0 0u/g ,酶解时间 80min ,m原料 :m水 =1∶2 ,pH 6 8。酶解所得可溶性蛋白经氨基酸分析仪检测 ,其氨基酸总量为 49 47mg/mL ,必需氨基酸占氨基酸总量的 41 0 % ,游离氨基酸含量为 6 3mg/mL ,肽含量为 87 2 %。     

响应面法优化制备牡蛎短肽工艺

【目的】探究前处理方式对酶解效果的影响,优化牡蛎短肽制备工艺。【方法】在确定高效酶种类和前处理方式的基础上,以氮回收率、短肽得率为指标对酶解时间、料液比、酶解温度、加酶量进行单因素试验,再利用响应面设计建立数学模型,以短肽得率为响应值,进行4因素3水平的响应面分析。【结果与结论】牡蛎经80℃热处理10 min后使用动物蛋白酶的酶解效果最佳。响应面结果显示,最佳酶解工艺为料液比(g/m L)1∶3.9、温度47℃、加酶量3 300 U/g、自然pH(6.5)、酶解3 h,其短肽得率为(58.53±1.20)%,比原酶解工艺提高24.8%。     

对虾蛋白自溶制备ACE抑制肽的工艺条件优化

以凡纳滨对虾为原料，以ACE抑制率为指标，利用响应面法对虾肉蛋白自溶制备ACE抑制肽的工艺条件进行了优化，即在酶解条件（pH值、温度、虾头虾肉质量比）和ACE（Angiotensin I-converting Enzyme，ACE）抑制率之间建立了数学模型Y=23．59—0．21X1＋0．84X2＋0．85X3—0．71X1^2-0．94X2^2-1．06X3^2＋0．088X1X2—0．46X1X3-0．87X2X3。分析表明，在3个因素中，虾头与虾肉比例对ACE抑制率的影响最为显著。优化后的工艺参数为：pH7．35，温度57．2℃，虾头与虾肉比例为1：1。根据回归方程的预测结果，反应时间为4h，其ACE抑制率达41．9％。     

响应面法优化南极磷虾酶法制备DPP-IV抑制肽工艺条件的研究

采用动物蛋白水解酶酶解制备南极磷虾二肽基肽酶-IV(DPP-IV)抑制肽,以DPP-IV抑制率和可溶性蛋白含量为主要指标,考察温度、反应时间、pH、酶添加量对南极磷虾的酶解效果。在单因素的基础上,依据中心组合实验设计原理,运用4因素3水平的响应面分析法,建立动物蛋白水解酶酶解南极磷虾制备DPP-IV抑制肽的二次多项式数学模型,并以DPP-IV抑制率为响应值作响应面。结果表明:南极磷虾酶法制备DPP-IV抑制肽的最佳工艺参数为酶解时间3.85 h、温度45.02℃、pH值7.58、酶添加量237.55 U/g原料;在此条件下,酶解液DPP-IV抑制率的预测值为64.82%,验证值为64.78%,优化方法可行。     

华贵栉孔扇贝酶法制备α-葡萄糖苷酶抑制肽工艺优化

【目的】为了进一步挖掘海洋贝类潜在的降血糖功能。【方法】选用华贵栉孔扇贝闭壳肌为原料,以抑制α-葡萄糖苷酶活性为评价指标,采用正交试验法和响应面分析法优化α-葡萄糖苷酶抑制肽的制备工艺。【结果】华贵栉孔扇贝(Chlamys nobilis)、马氏珠母贝(Pinctada fucata)和栉江珧(Atrina pectinate)等三种海洋贝类的闭壳肌酶解产物均对a-葡萄糖苷酶、a-淀粉酶和脂肪酶具有抑制活性;正交试验和响应面综合分析结果表明,华贵栉孔扇贝闭壳肌制备a-葡萄糖苷酶抑制肽的最佳工艺:复合蛋白酶酶添加量5 500 U/g,酶解温度57℃,酶解pH=7,酶解时间4 h,其酶解液中小肽含量21.64 mg/mL,a-葡萄糖苷酶的抑制率达到31.53%。【结论】利用响应面法可优化制备α-葡萄糖苷酶抑制肽的工艺。     

酶解法提取鱼油的工艺参数优化

利用蛋白酶酶解法从黄鳍金枪鱼（Thunnus albacares）加工的下脚料——鱼头中提取鱼油。以鱼油提取率和感官特征为指标，通过正交优化实验设计，获得了胰蛋白酶提取鱼油的最佳酶解工艺参数：酶解温度45℃，酶添加量1．5％．料液质量比1：1，酶解时间4h，酶解pH8。在该条件下．鱼油的提取率为4．34％，理化指标除过氧化值外均达到SC／T3502-2000的粗鱼油二级标准。多不饱和脂肪酸总含量高达38．47％,其中DHA和EPA的含量分别为23．63％和4．84％。     

对虾蛋白自溶制备ACE抑制肽的工艺条件优化

以凡纳滨对虾为原料,以ACE抑制率为指标,利用响应面法对虾肉蛋白自溶制备ACE抑制肽的工艺条件进行了优化,即在酶解条件(pH值、温度、虾头虾肉质量比)和ACE(Angiotensin I-converting Enzyme,ACE)抑制率之间建立了数学模型Y=23.59-0.21X1+0.84X2+0.85X3-0.71X12-0.94X22-1.06X32+0.088X1X2-0.46X1X3-0.87X2X3。分析表明,在3个因素中,虾头与虾肉比例对ACE抑制率的影响最为显著。优化后的工艺参数为:pH7.35,温度57.2℃,虾头与虾肉比例为1∶1。根据回归方程的预测结果,反应时间为4 h,其ACE抑制率达41.9%。     

Thermohaline structure inhomogeneity associated with polynia at the northern margin of Emery Ice-shelf

Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.     

Phylogenetic analysis of cultivable bacteria isolated from Arctic sea-ice

Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter.     

Information for authors

正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprchensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose is to publish achievements in fundamental research,applied     

Advances in Polar Science CONTENTS(Volume 25,2014)

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Guide to Authors： Journal of Mountain Science

<正>AIMS AND SCOPE(Editorial Policy)The Journal of Mountain Science(JMS)is devoted to mountains and their surrounding lowlands-ecoregions of particular global importance,with a particular emphasis on the important highlands/mountains in the world,such as the Tibetan Plateau,the Himalayas,the Alps,the Andes,the Rockies and many other mountain ranges of our planet.     

Journal of Mountain Science(JMS)

<正>The Journal of Mountain Science(JMS),founded in2004,is an international English-language journal on mountain sciences.JMS is supervised by the Chinese Academy of Sciences(CAS),sponsored by the Chengdu Institute of Mountain Hazards and Environment,CAS,published by Science Press China,and distributed by Springer exclusively throughout the world(excluding Mainland China).The JMS is published bimonthly,fulltexted in SpringerLink and CNKI,indexed/abstracted by     

Relationship of Arctic sea ice and Northern Hemispheric 500 hPa Polar vortices

Using the NCEP/NCAR reanalysis monthly 500 hPa height data on a 2.5 latitude-longitude grid and 1°×1° sea ice data,the polar vortex area,intensity index and arctic sea ice area index are calculated respectively,and the meridional distribution,period variation and the abrupts in the long range trend are analyzed to study their relationship.The results show that the meridional distribution of sea ice and polar vortex h-ave distinctive difference,the relative positions of them are different in the eastern and western hemispheres,and exept they have periods of 4 months,quasi half year,quasi year,4-5 years and 10 years commonly,and each of them has its own respective variation as well.The sea ice area is decreasing apparently since 1980's,so is the polar vortex area,but their abrupt changge time are different totally.The area of sea ice and polar vortex has prominent positive correlation,but the relationship of sea ice intensity,polar vortex intensity,polar vortex area is complicated.     

Author Index for Journal of Mountain Science Volume 11,2014,pp 1-1656

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Information for Authors

<正>The Journal of Ocean University of China(Oceanic and Coastal Sea Research)is a comprehensive academic quarterly sponsored by the Ocean University of China,published one volume per year.This journal is devoted to the publication of the theoretical and applied research