用SPME方法分析不同贮藏方式厚皮甜瓜香气成分的研究

采用固相微萃取(SPME)与气相色谱一质谱联用(GC-MS)的方法,对在6±0.5℃冷藏条件下,采用O24%～6%,CO2 0.2%～0.5%的气体成分进行CA贮藏和每48h处理1次,每次处理时间为3min,处理后臭氧浓度为0.45μL/L的臭氧间隙处理贮藏的新疆厚皮甜瓜"金凤凰"的香气成分进行了比较研究.贮藏52d时,上述两种贮藏方式的厚皮甜瓜中分别测定出30余种挥发性物质,其中CA贮藏的厚皮甜瓜中检测出20种酯类,占峰面积的85.49%,臭氧间隙处理的厚皮甜瓜中检测出17种酯类,占峰面积的67.15%.研究表明,酯类是构成厚皮甜瓜香气的主要成分.两种贮藏方式的厚皮甜瓜在贮藏52d时,挥发性物质的组成和相对含量差异显著,与臭氧间隙处理相比,O24%～6%,CO20.2%～0.5%的CA贮藏更能有效地保持厚皮甜瓜中的香气成分.     

1-MCP对火龙果低温贮藏期品质的影响

以白肉火龙果新品种晶红龙为试验材料,研究3种不同浓度的1-MCP处理对低温贮藏期火龙果品质的影响。结果表明,1-MCP熏蒸处理的整体效果优于对照,在贮藏前期(0～24 d)对抑制火龙果果实呼吸作用具有一定的作用;对照在贮藏18 d后出现腐烂,1-MCP处理贮藏期可延长3 d~6 d;1-MCP处理延缓了可滴定酸和VC含量的下降,抑制还原糖含量增加,显著延缓火龙果贮藏期的品质劣变。综合来看,以0.5μL/L和1.0μL/L 1-MCP处理对维持冷藏期间果实的保鲜效果最好。     

一氧化氮熏蒸对冬枣采后贮藏品质的影响

试验旨在研究不同浓度NO熏蒸处理对冬枣采后贮藏品质的影响。以白熟期冬枣为试验材料,分别以0,50, 100, 150和200μL/L一氧化氮(Nitric oxide, NO)气体熏蒸处理2 h后,在0±1℃条件下贮藏80 d。观察贮藏期果实阶段性的外观变化,同时分析测定其腐烂指数、失重率、硬度、可溶性固形物、呼吸强度和细胞膜渗透率的变化。结果表明:NO处理(浓度为50～200μL/L)能够不同程度地减轻白熟期冬枣果实表面出现腐烂斑点和软腐情况;降低果实的腐烂指数、失重率和细胞膜渗透率;抑制果实的呼吸强度;较好地保持果实的硬度和可溶性固形物的含量。在NO浓度为50～200μL/L范围内熏蒸对白熟期冬枣采后的贮藏品质有不同影响,其中以150μL/L处理2 h后在0±1℃条件下贮藏效果最好,贮藏期延长,腐烂指数降低,失重率降低,硬度保持较好,可溶性固形物含量维持较好,能抑制冬枣采后贮藏过程中的呼吸强度、抑制细胞膜渗透率的上升。     

不同浓度外源水杨酸对甜瓜果实抗病相关酶活性的影响

以伽师瓜和86-1甜瓜为实验材料,研究水杨酸(Salicylic acid,SA)处理对甜瓜果实抗链格孢侵染的影响。伽师瓜和86-1甜瓜经3、6、9 mmol/L水杨酸浸泡处理10 min,以蒸馏水处理为对照,接种Alternaria alternata,置于6℃冷库贮藏,测定抗病性相关酶活力。结果表明:SA处理可显著提高甜瓜果实PAL、SOD、CAT、POD、GLU、CHT活性,可有效提高甜瓜果实的抗病性,增强甜瓜果实对链格孢抗病能力。3 mmol/L SA处理可有效提高伽师瓜果实贮藏过程中抗链格孢侵染能力,6 mmol/L SA处理可有效提高86-1甜瓜果实贮藏过程中抗链格孢侵染能力。     

1-甲基环丙烯处理对芒果采后成熟过程的影响

以芒果为试材,研究0.25、0.50和1.0μL/L浓度的1-甲基环丙烯(1-MCP)室温熏蒸芒果24h对果实的转黄指数、呼吸速率、乙烯释放量、丙二醛含量以及脂氧合酶和过氧化物酶活性等指标的影响。结果表明:1-MCP熏蒸处理明显抑制果实的转黄指数及呼吸强度,对抑制乙烯生成有很好的作用;显著降低贮藏期间丙二醛含量,抑制膜脂过氧化作用及果实脂氧合酶和过氧化物酶活性,说明0.50μL/L的1-MCP浓度处理能够延缓芒果采后转黄与后熟衰老,抑制果实贮藏期品质的下降,从而延长芒果采后贮藏保鲜期。     

适宜臭氧处理对甜瓜采后品质的影响

以甜瓜西州密25号为实验对象,在温度6~8℃,RH80~85%条件下对甜瓜进行适宜的臭氧处理,通过臭氧发生器按照适宜的臭氧浓度和间隔处理时间在50 L的塑料桶中进行密封40 min处理,每次处理结束后去盖贮藏。研究甜瓜在42 d贮藏期中通过适宜臭氧处理观察其相关品质指标的动态变化,以及适宜臭氧处理对链格孢和镰刀菌的抑菌影响。实验表明:适宜臭氧处理(浓度4.28mg/cm~3、间隔时间24 h)后的甜瓜糖度和硬度平均每天仅下降0.07、0.03%,臭氧对其下降起到了明显的延缓作用,同时降低了42%的失重率,对镰刀菌和链格孢起到很强的抑菌作用且对链格孢有更好的抑菌效果,平均每天仅增长4.04 mm;适宜的臭氧处理对甜瓜采后低温贮藏品质有较好的保持作用,延长了贮藏期。本文为甜瓜采后低温贮藏保鲜提供了一定的理论基础。     

不同处理方式对厚皮甜瓜的贮藏保鲜效果研究

以陕西省阎良区厚皮甜瓜为试材,采用1-甲基环丙烯(1-MCP)、焦亚硫酸钠(Na2S2O5)、噻苯咪唑(TBZ)结合气调等处理方法,研究了厚皮甜瓜的采后生理变化及贮藏品质,得出了厚皮甜瓜的贮藏方法。结果表明,采用1-MCP结合Na2S2O5处理,能抑制苯丙氨酸解氨酶(PAL)和过氧化物酶(POD)的活性,使过氧化氢酶(CAT)和超氧化物岐化酶(SOD)活性处于较高水平,明显延缓厚皮甜瓜硬度的下降,抑制可溶性固形物含量快速上升,有效地减少果实腐烂,用该处理贮藏80d,果实腐烂指数0.37,商品果率80%。另外,厚皮甜瓜在TBZ结合气调的方式下贮藏也具有较好的贮藏保鲜效果。     

贝莱斯芽孢杆菌处理对厚皮甜瓜保鲜效果及保护酶活性的影响

为探究生防菌处理对厚皮甜瓜保鲜效果和保护酶活性的影响,本研究选用西州蜜25号厚皮甜瓜作为研究对象,通过在25 ℃和4 ℃条件下在厚皮甜瓜表面接种贝莱斯芽孢杆菌BG-2,测定贮藏期间拮抗菌在厚皮甜瓜表面定殖特性、保鲜效果和厚皮甜瓜过氧化物酶（Peroxidase,POD）、多酚氧化酶（Polyphenol oxidase,PPO）和苯丙氨酸解氨酶（Phenylalnine ammonialyase,PAL）活性的变化。结果表明,在25 ℃和4 ℃条件下,拮抗菌在厚皮甜瓜表面定殖数量均呈现先上升后下降的趋势且能稳定定殖。接种拮抗菌的厚皮甜瓜腐烂效果、抑制pH和可溶性固形物含量的下降显著优于对照组（P<0.05）。POD和PAL活性呈现先上升后下降的趋势,PPO活性在室温下呈现先上升后下降趋势,在低温下呈现缓慢上升趋势。25 ℃下,拮抗菌处理组POD在第20 d时酶活最高,PAL和PPO在第10 d时酶活最高;4 ℃下,拮抗菌处理组POD和PAL在第20 d时酶活最高。PPO处理在第40 d时酶活最高。且拮抗菌处理过的厚皮甜瓜酶活始终高于病原菌处理组。在25 ℃和4 ℃贝莱斯芽孢杆菌BG-2均能在厚皮甜瓜表皮上稳定定殖,抑制贮藏期厚皮甜瓜腐烂,延缓pH、可溶性固形物、POD、PPO和PAL酶活性下降,且BG-2和低温相结合对上述效果更好。本研究为延长新疆厚皮甜瓜贮藏期提供理论依据,为生防菌作用在厚皮甜瓜采后保鲜提供技术支持。     

不同温度、1-MCP浓度和薄膜包装对青脆李耐贮性的影响

比较了不同温度(4、10℃和常温)、不同浓度1-MCP(0.5μL/L、0.75μL/L和1.0μL/L)和不同薄膜(PE膜、PVC膜、微孔薄膜)包装青脆李贮藏期间果实品质的变化。结果表明:4℃条件下青脆李果实贮藏期从常温下的3-5d延长至16d左右,延长贮藏时间约10d,其中好果率大于90%,并有效保持青脆李果实硬度,抑制SSC、TA、可溶性糖含量的降低;0.75μL/L 1-MCP处理后的青脆李于4℃条件下贮藏期可达到25d,好果率大于90%,有利于抑制果实硬度和SSC含量的下降,有效维持青脆李果实糖酸含量;PE膜包装有利于抑制果实硬度、SSC的下降,微孔膜有利于抑制TA含量的下降,PVC膜能保持果实较高可溶性糖含量。4℃、0.75μL/L 1-MCP和薄膜包装分别为最适合于青脆李贮藏保鲜的单因素条件。     

1- 甲基环丙烯复合焦亚硫酸钠处理对厚皮甜瓜的保鲜效果

以陕西省阎良区厚皮甜瓜为试材,采用1-甲基环丙烯(1-MCP)、焦亚硫酸钠(Na2S2O5)以及二者结合的处理方法,研究厚皮甜瓜采后生理变化及贮藏品质。结果表明：1-MCP结合Na2S2O5处理能明显延缓厚皮甜瓜硬度下降,抑制可溶性固形物含量快速上升,有效少果实腐烂,同时抑制苯丙氨酸解氨酶和过氧化物酶的活性,使过氧化氢酶和超氧化物岐化酶活性处于较高水平。在这种处理方式下,贮藏80d后,果实腐烂指数0.37、商品果率80%。1-MCP结合Na2S2O5复合处理对厚皮甜瓜具有很好的保鲜效果。     

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。     

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.     

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.