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1.
火棘果红色素的超声提取与抗自由基性能研究   总被引:2,自引:0,他引:2  
利用超声波作用,提取火棘果红色素,考察了影响火棘果红色素提取的因素,包括提取溶剂、提取酸度、提取时间、物料比等.结果表明,超声波作用下提取火棘果色素的最佳条件是:溶剂为95%乙醇、pH=1、物料比1:16、提取时间30min、提取级数为二级,产率为26.9%,色价等于6.13.超声提取方法具有无毒、高效、快速等特点.测定了色素的抗氧化能力:在色素浓度为1.8 g/L时,羟基自由基清除率大于60%,超氧阴离子自由基的清除率大于27%.  相似文献   

2.
以蛹虫草子实体超微粉末为原料,优化了蛹虫草色素的提取工艺,并对虫草色素的抗氧化性进行了初步探究。在色素提取工艺优化的实验中,在功率为500 W的超声波辅助提取环境下,选取乙醇浓度、提取时间、提取温度、提取料液比为单因素,研究了它们对虫草色素提取的影响;在此基础上,选择对提取影响较大的乙醇浓度、提取时间、提取温度、料液比为影响因素进行正交试验,确定了超声波辅助提取蛹虫草色素的最佳工艺条件:提取温度55℃,料液比1:20,超声辅助提取30 min,乙醇浓度为80%。在蛹虫草色素生物活性研究中,用自由基清除试验对蛹虫草色素的抗氧化性进行了探究,结果发现:蛹虫草色素对1,2-二苯代苦味肼基自由基(DPPH·)、羟自由基(·OH)、超氧阴离子(O2-·)的清除有很好的效果。  相似文献   

3.
利用超声波提取法,以乙醇为溶剂对玉兰叶多酚进行提取。选择乙醇体积分数、料液比、超声温度和超声时间作为影响因素。在单因素实验的基础上,通过正交实验对玉兰多酚的提取条件进行优化,经紫外光照、添加剂、氧化剂、还原剂、金属离子和热处理后,研究了玉兰叶多酚的抗氧化稳定性。同时研究玉兰叶多酚对油脂基质的抗氧化性质。结果表明:以乙醇为提取溶剂时,玉兰多酚的最佳提取工艺为乙醇体积分数为80%,料液比1∶16,超声温度80℃,超声时间40 min。玉兰叶多酚对自由基清除作用试验表明,多酚对DPPH自由基和羟自由基均具有清除作用,对DPPH自由基清除能力较好。多酚提取物可以有效地延缓植物油及动物油的氧化,抗氧化能力随着玉兰叶多酚提取物添加量的增加而增强。  相似文献   

4.
以新疆昆仑雪菊为原料,采用超声-微波协同提取昆仑雪菊色素,在单因素试验的基础上,采用响应面试验设计,以雪菊色素色差值(E)为响应值,以浸取温度、浸提时间和料液比为影响提取过程中的3个因素进行试验设计;并测定雪菊色素提取液对DPPH自由基(DPPH·)、羟自由基(·OH)和超氧阴离子自由基(O~(2-)·)的清除能力。结果表明:超声-微波协同提取昆仑雪菊色素最佳工艺条件为:提取时间20 min,提取温度44℃,料液比1∶21,乙醇浓度50%,微波功率120 W,在此条件下提取的雪菊色素E为54.72,经过实际试验重复验证,平均雪菊色素E为53.7,相对误差为3.14%与预测值比较接近;雪菊色素对DPPH·、·OH和O~(2-)·清除作用明显,表明雪菊色素具有良好的抗氧化作用,可以作为天然抗氧化剂和进一步开发和利用。  相似文献   

5.
本文从向日葵花中提取黄色素,研究其抗氧化活性.结果表明,向日葵黄色素对DPPH、超氧阴离子自由基(O2-)、羟自由基(·OH)、过氧化氢(H2O2)都具有较强清除作用,并且随加入量的增加而增大.说明向日葵花黄色素是一种很有开发前景的抗氧化剂,具有很高的利用价值.  相似文献   

6.
松籽壳多糖超声辅助溶剂法提取及抗氧化性研究   总被引:1,自引:0,他引:1  
用超声波辅助溶剂法提取松籽壳中可溶性多糖,通过单因素和正交试验L9(34)优化提取工艺。并通过清除试验研究松籽壳多糖清除羟基自由基(.OH)和超氧阴离子自由基(O2-.)的效果。结果表明:超声波辅助提取松籽壳多糖的最佳工艺条件为超声时间30min,提取温度60℃,料液比1:50(m:V),超声提取次数1次,该条件下多糖含量为44.26%;松籽壳多糖具有较强的清除(.OH)能力,对(O2-.)的清除作用一般。  相似文献   

7.
桂皮油树脂的超声波提取及其抗氧化性研究   总被引:2,自引:0,他引:2  
以桂皮为原料,经超声波提取得桂皮油树脂.通过正交试验获得最佳提取条件,然后对桂皮油树脂清除DPPH.自由基和过氧化氢的能力进行了研究.实验表明:最佳提取条件为料液比为1∶15、浸泡时间为15h、超声时间为60 min、超声功率为1 kW;桂皮油树脂具有清除DPPH·自由基和过氧化氢的能力,随着浓度的增加,桂皮油树脂对DPPH.自由基和过氧化氢的清除作用逐渐增强.  相似文献   

8.
目的:研究超声波辅助法提取八角茴香挥发油的最佳工艺参数及体外抗氧化活性。方法:选取八角茴香为原料,以料液比、粉碎粒径、超声时间作为考察因素,采用单因素试验和正交试验,对超声波辅助提取八角茴香油的工艺参数进行了研究,同时以维生素C标准品作为对照,通过测定其对羟自由基、超氧阴离子自由基及DPPH自由基的清除能力考察其体外抗氧化活性。结论:3个考察因素影响超声波辅助提取法的程度依次为料液比粉碎粒径超声时间;提取工艺的最佳条件是料液比1∶15、粉碎粒径60目、超声时间30min、提取率(28.438±0.11)%。八角茴香挥发油对羟自由基、超氧阴离子自由基、DPPH自由基均有较强的清除能力,但均低于维生素C标准品;在一定浓度范围内清除能力随着浓度增加而增大,其半数清除率(IC50)分别为4.9422,7.8492,6.1980mg/mL。  相似文献   

9.
采用响应面法优化超声波提取酒糟中玉米黄色素的提取条件并对超声提取玉米黄色素进行抗肿瘤活性研究。在单因素试验的基础上,选取超声时间、固液比和超声波功率为关键因子,应用Box-Behnken中心组合进行3因素3水平的实验设计,以色素收率作为响应值,进行响应面分析(RSA)。结果表明,超声波法提取酒糟中玉米黄色素的最佳提取条件为:提取时间69.85min,超声功率744W,固液比1∶4.5(g:mL),提取率预测值137μg/g,验证值为132μg/g,与预测值的相对误差为3.8%;超声提取的酒糟玉米黄色素对Hela细胞、乳腺癌细胞具有较好的抑制作用。  相似文献   

10.
对生姜抗多种自由基能力进行检测。通过单因素试验和正交试验分析不同辅助处理方式(微波、超声、普通浸提)、溶剂种类、溶剂浓度、料液比、处理时间以及提取温度等对生姜提取物清除自由基能力的影响。结果表明:不同处理的生姜提取物均对2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基(ABTS+·)和1,1-二苯基-2-三硝基苯肼自由基(DPPH·)有明显的清除作用,对羟基自由基(HO·)的清除作用较小,对超氧阴离子自由基(O2-·)几乎没有清除作用。并且有机浸提溶剂对羟基自由基及超氧自由基具有清除作用。生姜提取物对各种自由基清除能力的大小依次为:ABTS+·﹥DPPH·﹥HO·。  相似文献   

11.
蛋白质水解度测定方法综述   总被引:27,自引:0,他引:27  
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。  相似文献   

12.
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.  相似文献   

13.
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。  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
百年风尚     
《中国服装(北京)》2013,(19):130-133
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。  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
矩阵乘积的行式,列式   总被引:1,自引:0,他引:1  
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.  相似文献   

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