猪、牛肉加热终点温度检测方法的研究

为满足肉类及肉制品加热终点温度监控需要,通过蛋白质SDS-PAGE电泳来检测加热终点温度指示蛋白乳酸脱氢酶含量,通过肉产品中加热与否的LDH SDS-PAGE电泳LDH量的变化来进行加热终点温度的检测,结果表明,建立的SDS-PAGE加热终点温度检测方法可以有效的进行鉴别检测需要。     

酶联免疫方法在牛肉加热终点温度检测中的应用

为保证肉类及肉制品的卫生安全,各国要求加热到一定的加热终点温度。研究通过免疫新西兰白兔获得加热终点温度指示蛋白乳酸脱氢酶的抗体,并建立了牛肌肉加热终点温度酶联免疫检测方法。     

猪牛肉加热终点温度酶联免疫检测方法的建立

为满足肉类及肉制品加热终点温度监控需要,通过免疫新西兰白兔获得加热终点温度指示蛋白乳酸脱氢酶的抗体,应用棋盘滴定法确定最适抗体包被浓度和酶标抗原浓度,用1%BSA-PBS稀释去除基质影响,从而建立了猪牛肉加热终点温度酶联免疫检测方法。     

应用同工酶电泳法区分巴氏奶与超高温灭菌奶的初探

利用同工酶电泳法分析巴氏奶与超高温灭菌奶中的过氧化物酶（POD），乳酸脱氢酶（LDH）和6-磷酸葡萄糖脱氢酶（G6PDH），结果表明：奶品经过85度以上的灭菌处理后过氧化物酶，乳酸脱氢酶的活性基本丧失，而6-磷酸葡萄糖脱氢酶在巴氏奶中还有较强的活性，在经过超高温灭菌后其活性也基本丧失。因此，奶样中6-磷酸葡萄糖脱氢酶活性的有无可以对巴氏奶和超高温灭菌奶进行鉴别。     

基于分子动力学模拟研究温度对乳酸脱氢酶活性的影响

乳酸脱氢酶是糖无氧酵解及糖异生的重要酶系之一，它能够催化丙酮酸形成乳酸，在食品发酵工业中具有很高的应用价值，但该酶易受高温影响，导致乳酸制品产量下降。为了研究不同温度对乳酸脱氢酶的构象及活性的影响，采用分子动力学模拟的方法，针对4种不同温度条件下（37、55、70和85 ℃）的乳酸脱氢酶分别进行了80 ns的计算模拟，分析了构象变化及酶活性中心的差异。研究发现，在37 和55 ℃条件下，乳酸脱氢酶比较稳定；当温度升高至70和85 ℃，乳酸脱氢酶的均方根误差、均方根波动、回旋半径值和溶剂可及表面积显著增加，而85 ℃ 时的蛋白二级结构已发生较大改变，这表明高温会导致蛋白质构象不稳定。对比37和85 ℃条件下该酶的底物丙酮酸的结合能力，发现高温会导致丙酮酸的结合位点残基之间的距离增大，进而破坏底物分子结合的微环境。因此，乳酸脱氢酶在温度超过70 ℃时发生变性，并随着温度的升高变性程度增加，进而导致酶活性丧失，不利于其在食品发酵等方面的应用。本研究在原子水平上分析了4种不同温度对乳酸脱氢酶的影响，揭示了其酶活性及构象变化的关键信息，为乳酸制品在发酵过程中选择合适温度提供了理论支撑。     

贮藏温度对哈密瓜蔗糖代谢途径中14种酶活性的影响

为了系统研究哈密瓜在不同贮藏温度条件下的蔗糖积累和呼吸代谢情况,在不同贮藏温度（0、5、10、 15、20、25、30、35、40、45 ℃）测定哈密瓜外果皮、内果皮、外果肉、中果肉、内果肉5 个部位蔗糖、乳酸、呼 吸代谢途径中14 种酶的基因表达活性及其变化情况。结果表明：哈密瓜果实5 个部位中蔗糖转化酶和乳酸脱氢酶活 性最高,其活性大小依次为：内果皮＞外果肉＞外果皮＞中果肉＞内果肉;哈密瓜在5 ℃贮藏时,包括蔗糖转化酶 和乳酸脱氢酶的14 种酶的活性均处于最低水平,可见5 ℃可有效地控制蔗糖代谢,是哈密瓜的最适贮藏温度。     

纤维素酶活性麦稃霉菌固体发酵物的流化床干燥试验

对含水分５０％～６０％（湿基）的纤维素酶（β－（１．４，１．３）－葡聚糖内切酶）活性麦稃霉菌固体发酵物湿坯，经过分散化预处理后，在不同的空气流速下进行的流化床干燥试验进行了研究。在干燥温度为７０℃、空气流速为３ｍ／ｓ的条件下，将含水分５５％的物料干燥至确定的终点８％（湿基），可以保留９０％左右的酶活率，其效果与冷冻干燥法和低温（４０℃）烘箱干燥法相当。认为湿基８％左右的物料水分含量应该是制品的干燥终点。对物料酶活性保留和流化床干燥控制有关的湿含量影响和干制品粒度级分的重量、水分含量和酶活含量分布也进行了试验研究。     

渗透化细胞转化生成苯乳酸的研究

Lactobacillus sp.SK007乳酸脱氢酶是催化苯丙酮酸转化生产苯乳酸的关键酶。实验中研究了渗透化剂对于Lactobacillus sp.SK007乳酸脱氢酶表观酶活的影响,优化了细胞渗透化处理过程;研究了pH和温度对于渗透细胞和粗酶液乳酸脱氢酶表观酶活及稳定性影响,优化了Lactobacillus sp.SK007渗透化细胞转化生产苯乳酸的工艺。渗透化过程:以2%乙醚为渗透剂,渗透时间2min,渗透化温度30℃;渗透化细胞转化生产苯乳酸工艺:苯丙酮酸底物浓度为5g/L,反应温度40℃,pH为6.0,转化时间为4h,PLA的产量达到3.38g/L。     

氯化亚铈对谷氨酸棒杆菌S9114生长和几种脱氢酶酶活性的影响

为了解单一稀土氯化亚铈(CeCl3)对谷氨酸棒杆菌的生物效应,研究了其对谷氨酸棒杆菌S9114的生长及谷氨酸脱氢酶(GDH)和乳酸脱氢酶(LDH)酶活的影响。结果表明,CeCl3在低剂量下促进S9114的生长,并显著激活其酶的活性;当CeCl3达到一定剂量时,开始抑制菌体的生长,并对其酶的活性产生抑制作用。     

服用不同剂量姜黄素对大鼠血清酶及肝、心肌组织运动损伤的影响

通过灌服不同剂量姜黄素，测试了大鼠在疲劳运动后血清肌酸激酶（CK）、谷草转氨酶（SGOT）、谷丙转氨酶（SGPT）、乳酸脱氢酶（LDH）的活性和心肌、肝组织超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH—Px）、过氧化氢酶（CAT）活性和丙二醛（MDA）含量。旨在研究服用不同剂量姜黄素对大鼠由于运动导致不同组织自由基损伤的保护作用。结果表明，服用不同剂量姜黄素使大强度运动大鼠血清CK、SGOT、SGPT、LDH活性有不同程度的下降；大鼠心肌、肝组织SOD、CAT、GSH—Px活性都有不同程度的升高、MDA含量显著降低（p〈0．05），并呈一定量效关系。结论：姜黄素对疲劳运动所致大鼠肝和心肌组织自由基损伤具有明显保护作用。     

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.     

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。     

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.     

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.     

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。     

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.     

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.     

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.     

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．