首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
一串红天然色素及其稳定性研究   总被引:8,自引:0,他引:8  
以新疆地产一串红(Salvia splendens Ker-Gawl)的花为实验材料,从光、温度、pH值、还原介质、氧化介质、防腐剂、金属离子等影响因子方向对色素的稳定性进行了初步研究。结果表明:该色素属于花青苷类色素;对光、温度等比较稳定;可在偏酸或中性介质中使用;耐还原性和耐氧化性较差;蔗糖、防腐剂以及大多数金属离子对色素的稳定性无不良影响,但Fe^3 、Pb^2+和Sn^2 对色素的稳定性有一定影响。  相似文献   

2.
蜀葵天然色素及其稳定性研究   总被引:10,自引:4,他引:6  
彭子模  孙健  滕云  高雁  彭宇 《生物技术》2003,13(1):13-15
以新疆地产蜀葵(Althaea rosea L.Cavan.)花为实验材料,用50%乙醇 0.5%盐酸为浸提剂,物料配比为1:10,提取出蜀葵花紫红色素,并从光、温度、pH值,氧化剂,还原剂,蔗糖,苯甲酸钠和不同金属离子对色素稳定性的影响进行了初步研究,结果表明:该色素在pH2时耐光性较好,温度在65℃以下和pH值4以下时色素稳定性较好,色素耐氧化性和耐还原性较差;蔗糖和苯甲酸钠对色素稳定性无不良影响,金属离子Cu^2 ,Fe^3 ,Sn^2 和Pb^2 对该色素稳定性有不良影响,Zn^2 对色素的稳定性只有轻微影响,而Al^3 ,Na^ ,Mg^2 ,K^ ,Fe^2 和Ca^2 对色素的稳定性则皆无不良影响。  相似文献   

3.
蜀葵紫红色素及其理化性质研究   总被引:2,自引:0,他引:2  
孙健  彭子模 《生物技术》2005,15(4):30-32
研究了蜀葵(Althaen rosea L.Cavan.)紫红色素的提取纯化工艺、理化性质。实验以蜀葵紫红色花瓣为材料,采用溶剂浸提法、硅胶柱层析法对色素进行提取纯化,效果较好。利用光谱扫描对该色素进行理化性质鉴定时发现:该色素属于花色苷类色素;色素耐光性好;耐氧化性、耐还原性较差;对热有一定的耐受性;防腐剂及多数金属离子对色素的稳定性无不良影响;但Fe^3+、Fe^2+、Cu^2+、Pb^2+、Sn^2+对色素具有不利影响。  相似文献   

4.
鸡冠花红色素理化性质及其稳定性研究   总被引:8,自引:0,他引:8  
李进  彭宇  彭子模 《生物技术》2004,14(1):21-24
目的:应用植物化学原理,对鸡冠花(Celosia cristata L.)红色素的理化性质及稳定性进行研究。方法:利用紫外-可见光吸收光谱、金属离子定性反应对色素作初步鉴定;观察光、热、pH值、还原剂、氧化剂、蔗糖、防腐剂、金属离子对色素稳定性的影响。结果:该色素易溶于水,在pH5以下,呈红色,初步定为花色苷类。其耐热性较差,耐可见光和紫外光性好;蔗糖和苯甲酸钠对色素稳定性无影响;H2O2对色素有不良影响;Na2SO3对色素的影响不显著;Zn^2 、Mg^2 、Ca^2 和Na^ 对色素稳定性无影响,而Fe^2 、Fe^3 、Cu^2 、Al^3 、Pb^2 、Sn^2 对色素有不良影响。结论:该色素属花色苷类,具水溶性,在一定条件下,稳定性好,是理想的植物色素。  相似文献   

5.
榆叶梅天然色素及其稳定性研究   总被引:21,自引:4,他引:17  
以新疆地产榆叶梅花为实验材料,对榆叶梅花食用色素提取时间、提取温度、物料配比进行不同组合的对比实验研究;对光、热、pH值、还原介质、氧化介质、蔗糖、防腐剂、维生素和金属离子等对色素的稳定性影响进行了研究。结果表明:榆叶梅花色一本正经不为水溶性色素属黄酮类色素。适用pH值范围较广,尤其酸性状态pH1-5最佳;蔗糖和防腐剂以及金属离子Zn^2 、Mg^2 、Ca^2 、K^ 、Na^2 对色素稳定性无不良影响;耐氧化剂与还原剂性能较差;而Fe^2 、Fe^3 、Cu^2 、Sn^2 、Pb^2 对色素稳定性有一定影响,其颜色相反发生改变。  相似文献   

6.
木莓果实红色素的理化性质及其稳定性   总被引:11,自引:2,他引:9  
对木莓(Rubus swinhoei Hance)果实中提取的红色素理化性质进行了探讨,并就光、温度、pH值、氧化还原介质、7种金属离子、葡萄糖、蔗糖和苯甲酸钠等对其稳定性的影响进行了研究。结果表明,木莓鲜果中总花色苷含量高,属水溶性性花色苷类。该色素对热的耐受性较好,但耐氧化还原性和耐Vc较差;7种金属离子中Na^ 、Mg^2 、Al^3 和较高浓度Mn^2 (≥5.0mmol/L)对该色素的稳定性较好,并有不同程度的护色效果,Zn^2 对其稳定性较好,而Fe^3 和Cu^2 对共稳定性有明显的影响或破坏作用;葡萄糖、蔗糖和苯甲酸钠无不良影响。  相似文献   

7.
万寿菊食用色素及其稳定性研究   总被引:9,自引:0,他引:9  
以万寿菊花序为实验材料,从光,热,pH值,还原介质,氧化介质,蔗糖,防腐剂,金属离子等对色素稳定性的影响进行了研究。结果表明:万寿菊色素的耐光,耐热,耐还原性较差;对氧化剂有一定耐受性,适用pH值范围广;蔗糖以及金属离子Na^ ,K^ 对色度基本上无影响,而Fe^2 ,Sn^2 ,Zn^2 对色素溶液颜色的稳定性只有微弱影响;而Fe^3 ,Cu^2 ,Ca^2 的加入则改变了色素溶液的颜色,对色度有一定的影响。  相似文献   

8.
杨梅水溶性红色色素的提取和性质的研究   总被引:12,自引:1,他引:12  
用离子交换层析法,从新鲜的杨梅[Myrica rubra Sieb et Zucc.]果中提取红色色素。最大吸收波长是515nm。34%色素水溶液达到饱和,几乎不溶于乙醇。温度、光和pH值的改变对色素稳定性均有影响。色素对Mg^2 和Fe^3 金属离子敏感性强。大多数食品添加剂对色素稳定性影响不大,但蔗糖对稳定性有影响。色素耐氧化性较弱,而耐还源性较强。色素的毒性实验表明:无毒性。  相似文献   

9.
多花野牡丹红色素的提取及其稳定性研究   总被引:6,自引:0,他引:6  
本文对多花野牡丹(Melastoma affine)果实胎座的色素进行了理化性质的探讨,对光、温度、氧化还原介质、7种金属离子、葡萄糖、蔗糖、苯甲酸钠对色素稳定性的影响进行了研究。结果表明,该色素为水溶性花青苷类色素,它在60℃以下稳定性较好,对光的耐受性较差。色素在酸性条件下稳定性好,耐还原性也较好,但耐氧化性较差。7种金属离子中,Fe^3 、Cu2 、Mn2 、Zn2 对色素有明显降解作用,而Na 、Mg2 、A13 对色素稳定性较好并有不同程度的护色作用。葡萄糖、蔗糖、苯甲酸钠对色素无不良影响。  相似文献   

10.
以新鲜菠菜、橘皮、番茄为原料,采用溶剂萃取法提取叶绿素、橘黄素、番茄红素,以吸光度为判断指标,研究了温度、光照、pH及金属离子对3种天然色素稳定性的影响。结果表明:橘皮色素稳定性较好,较耐热和耐光,pH稳定性较好;叶绿素耐热性和耐光性较差,酸性条件下较稳定;番茄红素稳定性最差,有一定的耐热性,不耐光,光照和紫外光下都易分解,不耐酸碱,酸性条件更不稳定。3种色素抗Mg2+、Na+、Ca2+等3种金属离子干扰能力较强,Cu2+、Fe3+对3种色素稳定性影响较大。  相似文献   

11.
12.
13.
14.
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

15.
16.
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

17.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

18.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

19.
20.
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号