马氏珠母贝肉酶解产物ACE抑制活性的研究

利用胰酶、枯草杆菌中性蛋白酶,在50℃、pH为7.0～8.0,m(贝肉)∶V水=1∶3的条件下,对马氏珠母贝肉进行双酶水解4h制备得到酶解产物及残渣。利用Alcalase2.4L、胃蛋白酶、复合蛋白酶、木瓜蛋白酶对残渣进行再次酶解。结果表明:残渣蛋白质含量按干基计达54.2%;Alcalase 2.4L、复合蛋白酶、木瓜蛋白酶对残渣的酶解效果较好;残渣的木瓜蛋白酶酶解产物ACE抑制活性较强;马氏珠母贝肉酶解产物清除自由基活性较强的组分分子量为944u,残渣木瓜蛋白酶酶解产物清除自由基活性较强的组分分子质量在1300～259u。     

合浦珠母贝肉短肽的分离及其抗氧化活性研究

为制备具有抗氧化能力的合浦珠母贝肉活性肽,本文采用Sephadex G-25分子筛层析法对合浦珠母贝肉酶解产物进行分离,测定分离到的各活性组分分子量及其总抗氧化活性、DPPH自由基清除能力及羟自由基清除能力。结果表明,合浦珠母贝肉酶解产物经Sephadex G-25分离得到6个主要活性组分,相对分子量分别为1437.5、833.7、421.9、244.7、89.0、17.4u,其中功能短肽F1(1437.5u)、F2(833.7u)、F4(244.7u)的抗氧化效果较强,特别是F2(833.7u)短肽具有最强的总抗氧化能力、DPPH自由基清除能力及羟自由基清除能力。该研究为合浦珠母贝肉抗氧化活性肽的开发提供理论技术依据。     

几种南海贝类酶解产物的生物活性及其分子量分布研究

对菲律宾蛤仔、波纹巴非蛤、马氏珠母贝双酶水解产物的自由基清除活性和血管紧张素转化酶（ACE）抑制活性及分子量分布进行研究。结果表明：3种贝类酶解产物均具有清除羟自由基、超氧阴离子、二苯基苦基苯肼（DPPH）等自由基的活性以及ACE抑制活性;3种贝类酶解产物对超氧阴离子的清除作用均较弱;羟自由基清除活性较强的是菲律宾蛤仔酶解产物,其高活性组分的分子量在1479～851 Da之间;DPPH自由基清除活性较强的是菲律宾蛤仔酶解产物,其高活性组分的分子量在1479～851 Da之间;ACE抑制活性较强的是波纹巴非蛤酶解产物,其高活性组分的分子量在633—303 Da之间。     

马氏珠母贝肉酶解产物清除自由基活性的研究

对马氏珠母贝肉的风味酶酶解产物对超氧阴离子自由基、羟自由基及DPPH·的清除效果进行了研究.结果表明,马氏珠母贝肉酶解产物对三种自由基均有一定的清除活性,量效关系明显;其清除O2-·、·OH、DPPH·三种自由基的IC50分别为1.513、1.423、2.618mg/mL,清除自由基能力总体高于牡蛎和海湾扇贝提取物.     

合浦珠母贝肉抗氧化肽的结构分析

为探明从合浦珠母贝肉中酶法制备得到的抗氧化肽的结构,采用基质辅助激光飞行时间质谱技术测定反相高效液相色谱(reverse phase High-performance liquid chromatography,RP-HPLC)分离合浦珠母贝肉酶解产物所得各组分的分子量,并对其中具有较强抗氧化能力的组分进行了二级质谱结构解析.结果表明,水解液经RP-HPLC分离,得到抗氧化活性较强的五个肽段组分A、B、C、D和E,其对应的相对分子量分别为1022.54、1334.60、1494.75、1085.60、1288.82和1304.83u.其中对苯代苦味肼基自由基(DPPH·)具有最强清除能力的是C组分肽,其氨基酸序列为Val-Ala-Thr-Gly-Leu-Arg-Lys-Glu-Gly-Val-Val-Gly-Gly-Pro-Arg.以上研究结果初步揭示了合浦珠母贝肉抗氧化肽的结构与抗氧化活性的关系.     

酶解中国毛虾制备清除羟自由基活性产物的研究

研究以高产低值的中国毛虾为原料,通过测定酶解物对Fenton体系产生的羟自由基的清除效果,从风味酶、复合酶、中性蛋白酶、Alcalase2.4L等10种常用蛋白酶中筛选出Alcalase2.4L作为酶解中国毛虾制备清除羟自由基活性酶解物的水解酶;以羟自由基清除率为指标,利用正交实验对酶解条件进行优化,将优化酶解条件下的酶解产物进行SephadexG-15凝胶色谱分离(1.6cm×68cm),测定分子量分布并收集各吸收峰。结果表明:Alcalase2.4L在温度55℃、pH9.0、酶底物浓度比[E/S]为12.0AU/g、时间3h的水解条件下,酶解物对羟自由基清除率为84.6%,水解度为26.28%,平均肽链长为3.81。Alcalase2.4L酶解物凝胶色谱分离得到一个较强羟自由基清除活性的组分分子量范围是2259～869,IC50为0.385mg/mL,肽链长度在22.4～7.7之间。     

海湾扇贝酶解产物清除自由基活性的研究

利用双酶(胰酶0.3%和枯草杆菌中性蛋白酶0.8%)。在50℃、pH值7.0～8.0、料水比1:3的条件下,对海湾扇贝肉酶解4h后制备得到产物.该酶解产物对羟自由基的清除活性IC_(50)为2.01 mg/mL,对超氧阴离子的清除活性IC_(50)为9.54 mg/mL,对DPPH自由基的清除活性IC_(50)为5.90 mg/mL。Sephadex G-15(1.6 cm×68 cm)凝胶色谱结果表明,该酶解产物中分子质量分布在1450～288 u,肽链长度在13.2～2.6的组分具有较强的清除羟自由基和DPPH自由基活性。     

鳙鱼肉酶解工艺及其产物清除羟自由基活性的研究

以高产低值的鳙鱼肉为原料,通过测定水解度及酶解产物对Fenton体系产生的羟自由基的清除效果,从胃蛋白酶、Alcalase2.4L、木瓜蛋白酶、胰酶4种常用蛋白酶中筛选出木瓜蛋白酶作为酶解鳙鱼肉制备清除羟自由基活性酶解物的水解酶;以羟自由基清除率为指标,利用正交试验对酶解条件进行优化,将优化酶解条件下的酶解产物进行高效液相色谱分离,测定分子量分布。结果表明:木瓜蛋白酶在温度45℃、p H7.0、酶加量2%、底物浓度20%、时间3 h的水解条件下,酶解产物对羟自由基清除率达76.13%。木瓜蛋白酶酶解物利用高效体积排阻色谱测定其主要分子量范围是2 691~32 u。     

鲤鱼肉酶解物清除羟自由基的研究

通过测定鲤鱼肉酶解物对Fenton体系产生的·OH的清除效果,从木瓜蛋白酶、胃蛋白酶、胰蛋白酶、复合蛋白酶和复合风味蛋白酶中,筛选出复合蛋白酶作为酶解鲤鱼肉制备具有清除羟自由基活性酶解物的水解酶.用响应面分析法(RSM)对该酶的水解条件进行优化,得到最佳酶解条件为:温度55℃、酶解时间1.5 h、pH=6.5、酶加量为250 U/g底物、底物质量分数为25%,在此条件下酶解物的水解度为4.5%.利用Sephadex G-15凝胶层析测定酶解物分子量分布,结果显示,活性肤分子量为477 u～1 058 u.     

罗非鱼鱼肉及组分蛋白酶解产物的抗氧化特性

采用胃蛋白酶、中性蛋白酶、Alcalase2.4L碱性蛋白酶分别酶解罗非鱼肉蛋白,研究比较不同蛋白酶在1、2、4、6、8h对罗非鱼肉蛋白的酶解效果及产物的抗氧化活性,结果表明:3种酶的酶解产物都具有一定的抗氧化活性,中性蛋白酶酶解产物的水解度和蛋白回收率最高,胃蛋白酶酶解产物对DPPH自由基和羟自由基的清除效果最好;综合各项指标选择中性蛋白酶对罗非鱼肉的组分蛋白(肌原纤维蛋白、肌浆蛋白、基质蛋白)进行4h酶解,研究比较不同组分蛋白的酶解效果及产物的抗氧化活性,结果表明:组分蛋白中基质蛋白酶解产物的蛋白回收率最高,为89.8%,肌原纤维蛋白酶解产物的水解度最高,为10.1%,肌浆蛋白酶解产物的抗氧化活性最好,羟自由基和DPPH自由基的IC50值分别为12.352mg/m L和3.554mg/m L。     

蛋白质水解度测定方法综述

对目前国内外常用的蛋白质水解度测定方法进行了综述，其中pH—state方法是通过滴定水解过程中释放的质子测定DH；OPA、TNBS及国内常用的水合茚三酮和甲醛等测定方法是利用游离氨基的反应测定DH。     

SEROLOGIC IDENTIFICATION OF SPECIES OF ORIGIN OF SAUSAGE MEATS

SUMMARY: A partially purified immunoglobulin G (lgG) solution prepared from the serum of species to be tested was heated to the specifications for sausages. The resulting supernatant fluid was decanted and the precipitate washed with saline and used to immunize rabbits. The supernatant fluid was used to sensitize tanned sheep red blood cells. The immune serum was rendered monospecific by absorptions with heterologous, heated lgG precipitates. A sample of monospecific immune serum was absorbed with a washed homogenate of sausage. Aliquots of the monospecific immune serum, both untreated and sausage absorbed, were tested with cells sensitized with the homologous heated lgG supematant fluid. A significant reduction of titer by sausage absorption indicated that the sausages contained the meat homologous to the immune serum.     

BASIS OF STABILITY OF AMINE SALTS OF LINOLEIC ACID

SUMMARY— The mechanism and generality of the known stabilization against autoxidation conferred on linoleic acid by certain basic amino acids, such as lysine and arginine, was investigated. Basic amino acids were the only class of compounds found to confer the effect. However, the smallest basic amino acid, 2,3-diaminopropionic acid, was not effective, nor was αβω-diaminc acid, 3,6-diaminohexanoic acid, although a simple isomer of lysine. The stabilization was observed only in the solid phase. Inclusion of sodium chloride in the solid matrix was deleterious to the effect. A large number of physical and chemical observations were made and correlated but it has not been possible to draw detailed conclusions about the mechanism of stabilization, nor can a detailed structure of the stabilized complex be suggested. The cause of the phenomenon appears to be closely associated with the physical arrangement of the ions in the crystal lattice.     

百年风尚

一场流光溢彩、赏心悦目的展览,一段百年风尚演进的传奇旅程,一次东西方文化艺术的完美对话。2013年9月13日,“博萃臻艺一中西方珍宝艺术展”在辽宁省博物馆举行了隆重的开幕仪式,法兰西共和国驻华大使白林女士、辽宁省文物局局长丁辉先生、辽宁省博物馆馆长马宝杰先生、卡地亚全球总裁兼首席执行官邓阁仕先生、卡地亚区域行政总裁（北亚洲）陆慧全先生、卡地亚中国区首席执行官陆意斯先生、辽宁省文物店总经理张春鹰先生,以及众多文化界与文博界的贵宾齐聚一堂,共同见证了这场文化艺术盛事。     

聚多元羧酸盐的合成及应用

研究了聚多元羧酸盐的合成方法及反应机理,将其应用于洗涤剂和PVC制品中分别代替三聚磷酸钠和邻苯二甲酸二丁酯,证明有良好效果。     

EFFECTS OF TYPES OF FAT AND OF RATES AND TEMPERATURES OF COMMINUTION ON DISPERSION OF LIPIDS IN FRANKFURTERS

ABSTRACT— The effect of time, temperature and rpm of comminution of emulsions was determined on the dispersion of approximately 25% of beef fat, pork fat or cottonseed oil in frankfurters. The numbers of lipid particles 5 μ or less in diameter increased in frankfurters containing either beef or pork fat as comminution was continued to higher temperatures, with pork fat dispersed more thoroughly. Fat tended to separate from frankfurters containing beef fat in particles 200 μ or more in diameter. In contrast, no specific degree of dispersion of particles 5 μ or less in diameter consistently indicated emulsion stability, or its lack. Increased rpm during comminution produced an increased dispersion of beef or pork fat. Under the same conditions pork fat was dispersed more finely than beef fat. Dispersion of cottonseed oil produced finely dispersed particles beyond the resolution of light microscopy, as was confirmed by electron microscopy which showed a substantial number of particles to be less than 1 μ in diameter.     

DEVELOPMENT OF CHAINS OF CELLS OF SACCHAROMYCES CEREVISIAE DURING FERMENTATION

The lengths of chains of cells of Saccharomyces cerevisiae were studied during fermentation. Pitching yeast generally contained about half of the total number of cells as two-celled chains. The chain lengths varied during the subsequent fermentation and the variations were characteristic of the strain. Electronic counting assessments of chain length were unreliable.     

STABILITY OF AQUEOUS EMULSIONS OF THE ESSENTIAL OIL OF HOPS

Hop oil emulsions prepared from different varieties of hops have been found to exhibit enhanced physical stability on the addition of blends of the emulsifiers Span 20/Tween 80 or Span 60/Tween 60. Examination of the particle size and volume distributions of an emulsion by use of a Coulter Counter was found to be an excellent method of monitoring its stability. An indication as to the relative efficiency of emulsifiers can be obtained from Coulter Counter measurements on hop oil emulsions after storage for 4 days. The use of an ultracentrifuge provies a rapid means of testing emulsion stability and hence the effectiveness of emulsion stabilizers.     

矩阵乘积的行式,列式

给出了ｍ×ｍ矩阵与ｍ×ｎ矩阵的行（列）式的表达式．若Ａ＝ａ１１ａ１２…ａ１ｍａ２１ａ２２…ａ２ｍ……ａｍ１ａｍ２…ａｍｍＢ＝ｂ１１ｂ１２…ｂ１ｎｂ２１ｂ２２…ｂ２ｎ……ｂｍ１ｂｍ２…ｂｍｎ分别是ｍ×ｍ，ｍ×ｎ矩阵，则｜Ａ｜｜Ｂ｜＝｜ＡＢ｜＋∑ｉ１＜ｉ２＜…＜ｉｔｊ１＜ｊ２＜…＜ｊｔ１≤ｔ≤ｍｎ－ｔ≥ｍＮＢｉ１ｉ２…ｉｔｊ１ｊ２…ｊｔＮＡＢ１…ｍ（－１）ｓｔ＋１ｊｔ＋１…（－１）ｓｎｊｎ其中ｉ１，ｉ２，…，ｉｔ是１，２，…，ｍ中ｔ个数码；ｊ１，ｊ２，…，ｊｔ，ｊｔ＋１，…，ｊｎ是１，２，…，ｎ的一个排列；ｓｒ＝π（ｊ１，ｊ２，…，ｊｔ，ｊｒ）（ｒ＝１，２，…，ｎ）是排列ｊ１，ｊ２，…，ｊｔ，ｊｒ的反序数．     

ANALYTICAL CHARACTERIZATION OF THE PRODUCTS OF NONENZYMATIC GLYCOSYLATION OF LYSOZYME

The quantitative analysis of the reaction products of the water activity dependent nonenzymatic glycosylation of lysozyme was not straightforward. Difficulties arose in the determination of the number of bound glucose molecules because glycosylation leads to glucose mediated protein aggregation, and the likely presence of a mixture of relatively labile Schiff-base intermediates, and the more stable ketoamine products generated by Amadori rearrangement. Polyacrylamide gel electrophoresis was used to monitor protein aggregation; periodate oxidation, nuclear magnetic resonance (NMR), and oxalic acid hydrolysis combined with HPLC, emerged as the most promising methods to quantitate the degree of glycosylation. Possible interpretations are advanced to explain the apparent discrepancies in degree of glycosylation suggested by the different analytical methods evaluated.