洋葱黄酮的提取条件及抗氧化活性的研究

为研究超声波辅助乙醇提取洋葱黄酮最佳工艺和抗氧化活性。采用正交实验,研究乙醇体积分数、超声时间、浸提时间和料液比对洋葱黄酮提取量的影响,测定了在最优条件下提取洋葱黄酮的还原力和对羟自由基的清除率。结果表明,洋葱黄酮最佳提取工艺条件为乙醇浓度70%,超声波处理时间5min,浸提时间1.5h,料液比1∶15(m∶V),该条件下洋葱黄酮的提取量为40.17mg/g。0.5mg/mL洋葱黄酮与0.5mg/mLVC还原力相等;洋葱黄酮对羟自由基的清除率随着溶液浓度(0～1.2mg/mL)的增加而增大,浓度为1.2mg/mL的黄酮溶液清除率为32.42%。实验表明洋葱黄酮提取物具有较强的抗氧化活性,可作为抗氧化剂或为研制功能食品提供资源。      

洋葱中黄酮类化合物的提取及其体外抗氧化活性研究

对洋葱中黄酮类化合物提取的最佳工艺条件及其体外抗氧化活性进行了研究.在提取过程中通过单因素试验分析了乙醇浓度、液料比、提取温度、提取时间对提取率的影响.在此基础上通过正交试验得到了洋葱黄酮类化合物提取的最佳工艺条件,即乙醇浓度70%,液料比20 ∶ 1,温度70℃,时间1.5h.体外抗氧化实验结果表明洋葱黄酮类化合物具有较强的还原力,对超氧阴离子自由基和羟自由基具有较强的清除能力,即洋葱黄酮类化合物具有较强的体外抗氧化活性.     

洋葱皮总黄酮纤维素酶法提取及抗氧化研究

采用中心组合试验设计研究纤维素酶法辅助提取洋葱皮中总黄酮的工艺条件,并对洋葱皮总黄酮的抗氧化活性进行测定。结果表明：洋葱皮总黄酮最佳提取工艺为纤维素酶用量0.52%、pH5.0、提取温度48℃、提取时间105min、料水比(g/mL)1:40,在此条件下,提取率为2.32%。洋葱皮总黄酮清除DPPH自由基和羟自由基的IC50分别为3.751、4.267μg/mL;同时洋葱皮黄酮还原能力较强,高于茶多酚。洋葱皮总黄酮抗氧化性强,是一种天然有效的抗氧化剂。     

紫洋葱皮中花色苷稳定性和抗氧化活性研究

研究紫洋葱皮花色苷在不同条件下的稳定性和抗氧化活性。在不同pH、温度、光照和金属离子条件下考察紫洋葱皮花色苷的稳定性,用体外抗氧化体系为模型,研究其对DPPH自由基的抗氧化活性。结果显示:pH为5时花色苷稳定性好;60℃以下稳定性良好;光照可促进花色苷分解;金属离子Zn2+、Cu2+、Ca2+对花色苷稳定性影响较大。抗氧化活性研究结果表明紫洋葱皮花色苷具有一定的清除DPPH自由基能力,其清除效果好于VC。     

玉叶金花黄酮提取工艺优化及抗氧化研究

以玉叶金花为原料，通过超声波辅助酶法提取玉叶金花黄酮，利用单因素和响应面法优化提取工艺，然后采用锐孔法将提取的黄酮制成微胶囊，并分析黄酮及其微胶囊在不同温度下的抗氧化能力。结果表明：玉叶金花黄酮最佳提取工艺为：乙醇质量分数58%、料液比1:99(g/mL)、酶添加量80 mg/mL、超声时间55 min，含量为142.3 mg/g。抗氧化能力结果显示：温度对玉叶金花黄酮ABTS自由基清除能力和总抗氧化能力影响次序为90℃>60℃>30℃，对其微胶囊的影响次序为30℃>60℃>90℃。黄酮在30℃下保温10 h时，ABTS自由基清除率和总抗氧化能力分别下降了10.4%和24.22%；而微胶囊在90℃下保温10 h,ABTS自由基清除率下降了1.31%，总抗氧化能力上升了2.96%。整体而言，黄酮抗氧化能力>微胶囊抗氧化能力，但微胶囊热稳定性更好。     

乙醇/磷酸氢二钾双水相体系提取洋葱黄酮工艺条件研究

该文对乙醇/磷酸氢二钾双水相体系提取洋葱黄酮的工艺条件进行研究,考察乙醇质量分数、磷酸氢二钾质量分数、洋葱粉添加量、提取温度和提取时间对洋葱黄酮提取率的影响。通过响应面试验设计及分析确定最佳提取条件。结果表明,乙醇/磷酸氢二钾双水相体系提取洋葱黄酮的最佳条件为:乙醇质量分数41.8%,磷酸二氢钾质量分数22%,洋葱添加量0.24 g,提取温度50℃、提取时间30 min,在此条件下,洋葱黄酮的提取率达5.32%。     

甘草总黄酮提取工艺及总抗氧化活性研究

研究了甘草样品1和甘草样品2中总黄酮的提取方法,分别优化了提取甘草黄酮的工艺条件,采用氧还法测定样品提取前后的总抗氧化活性。结果表明乙醇回流法提取样品1中甘草总黄酮的最佳工艺条件是:乙醇浓度100%,料液比1:2500,提取温度90℃,提取时间3h;水提法提取样品2中甘草总黄酮提取的最佳工艺条件是:料液比1:1000,提取温度40℃,提取时间1h。两种甘草样品的总抗氧化活性在一定范围内与浓度呈线性关系,样品1总抗氧化活性提取后比提取前增加了1.25倍,样品2提取后比提取前增加了1.02倍;样品1总黄酮提取率比样品2高约4倍,而样品2提取后的黄酮总抗氧化活性比样品1高,这可能是由于不同样品中甘草黄酮组成的差异以及溶解性差异所致。      

甘草总黄酮提取工艺及总抗氧化活性研究

研究了甘草样品1和甘草样品2中总黄酮的提取方法,分别优化了提取甘草黄酮的工艺条件,采用氧还法测定样品提取前后的总抗氧化活性。结果表明乙醇回流法提取样品1中甘草总黄酮的最佳工艺条件是:乙醇浓度100%,料液比1:2500,提取温度90℃,提取时间3h;水提法提取样品2中甘草总黄酮提取的最佳工艺条件是:料液比1:1000,提取温度40℃,提取时间1h。两种甘草样品的总抗氧化活性在一定范围内与浓度呈线性关系,样品1总抗氧化活性提取后比提取前增加了1.25倍,样品2提取后比提取前增加了1.02倍;样品1总黄酮提取率比样品2高约4倍,而样品2提取后的黄酮总抗氧化活性比样品1高,这可能是由于不同样品中甘草黄酮组成的差异以及溶解性差异所致。     

沙棘叶黄酮的提取及其对抗氧化性的影响

目的:利用不同溶剂对沙棘叶黄酮进行提取,研究沙棘叶黄酮的提取及其对抗氧化性的影响,综合提取温度和时间,确定常规条件下提取沙棘叶中抗氧化成分的最佳条件,为沙棘叶抗氧化性的研究提供依据。方法:采用紫外-可见光分光光度法,以芦丁作为对照品,进行检测实验。结果:溶剂对沙棘叶黄酮的提取率、抗氧化性影响较大。结论:沙棘叶中抗氧化物质的最佳提取条件为在30℃下,用80%（v/v）甲醇溶液提取4h。      

钩藤提取物抗氧化作用的研究

对钩藤以正己烷、乙酸乙酯、甲醇在索氏提取器中依次提取4 h,并对乙酸乙酯提取物和甲醇提取物进行了色谱分离,测定了各成分的抗氧化活性,通过显色反应和光谱分析对各成分进行了初步鉴定.结果表明,钩藤中有两种黄酮苷元和一种黄酮苷的抗氧化活性比BHT强,两种黄酮苷与BHT相近,3种酚酸和几种羟基蒽醌甙也有较强的抗氧化能力,但钩藤碱的抗氧化能力较差.     

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。     

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.     

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.     

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．