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 218 毫秒
1.
对桂花种子皮黑色素的还原性、金属鏊合性能进行了研究,并测定了其金属含量。结果表明,该天然黑色素的还原性比人工合成抗氧化剂BHT强,且随着黑色素浓度的增大而增强;同时该黑色素与金属铁离子鏊合能力非常有限,在0.05~0.3mg/mL金属鳌合能力只有1.4%~3.2%;该黑色素还含有大量Fe、Mn、Cu等微量元素。  相似文献   

2.
从工业发酵生产井冈霉素的吸水链霉菌5008发酵液中提取了一种黑色素,采用光谱法研究了光、温度、p H、还原剂、氧化剂、金属离子和食品添加剂对该色素稳定性的影响,并进行红外光谱分析,初步推测该色素的结构。结果表明:该色素具有较好的光、热稳定性和抗紫外辐射能力,具有一定的抗氧化性和抗还原性;p H值对该色素影响较明显,强酸性条件下色素会产生沉淀并变色,中、碱性条件下较稳定;Ca2+、Mn2+、Fe3+对色素的影响较大,Al3+能够对色素起到保色作用,而Mg2+、K+、Na+对色素影响较小;常见食品添加剂蔗糖和葡萄糖能增加色素稳定性,碳酸氢钠、苯甲酸钠对色素稳定性影响较小,柠檬酸对色素影响较大。红外光谱图表明,该色素的基本结构单元可能是吲哚环。该研究对工业发酵中的副产物加以充分利用,为天然色素的开发提供了理论依据和可能性。  相似文献   

3.
R362菌株产黑色素提取及稳定性研究   总被引:10,自引:2,他引:8  
通过液体培养R362菌株,提取其产生的黑色素,并研究酸度、温度、光照、碳水化合物、氧化剂、还原剂、金属离子对色素稳定性的影响。结果表明:该色素的最大吸收峰为390nm,在碱性条件下较稳定,在酸性条件下易褪色;热、光、碳水化合物对色素稳定性无影响,色素对H2O2和Na2SO3较敏感;几种常见的金属离子(除Fe3 )对色素色泽无影响。  相似文献   

4.
利用氨溶液提取、盐酸水解、多种有机溶剂萃取沉淀等工艺手段分离纯化了桂花种子皮黑色素,随后对黑色素的脂质抗氧化性能进行了研究,并测定了其总酚物质含量。结果表明,该天然黑色素能够显著抑制蛋黄的脂质过氧化,且具有明显的量效关系,其IC50为0.135mg/ml。同时该天然黑色素中含有丰富的酚类物质,1mg天然色色素中总酚的含量相当于12.5mg邻苯二酚.  相似文献   

5.
以氨水溶液提取、酸水解、有机溶剂洗涤、酸沉淀等工艺从红茶中分离纯化茶叶黑色素,并对其理化性质、光谱特征和清除DPPH自由基能力进行研究。结果表明,该天然黑色素不溶于水、酸和有机溶剂,对光、热、碱和还原剂稳定,Cu2+、Ca2+、Zn2+等金属离子对该色素有护色、增色作用,Fe3+、Al3+有一定的减色作用;茶叶黑色素中总酚含量为82.8μg/mg(以没食子酸计);具有较强的清除DPPH自由基能力I,C50为58.4μg/mL,是一种非常有潜力的天然黑色素和抗氧化剂资源。  相似文献   

6.
十种天然黑色素稳定性研究   总被引:1,自引:0,他引:1  
以黑香米、黑小米、黑大豆、黑绿豆、黑苦荞、黑小麦、黑花生、黑玉米、黑芝麻、黑红薯为原料,研究了10种天然黑色素的特征吸收波长和稳定性.结果表明:10种天然黑色素在紫外区有明显的特征吸收峰;黑苦荞、黑红薯色素光照下降解最为明显,光照对其余黑色素也有不同程度的影响;除黑苦荞色素外,其余黑色素在80℃以下具有良好的热稳定性;过氧化氢、亚硫酸钠能使黑色素发生较大程度的降解;氯化钠、蔗糖、笨甲酸钠、Ca2+、Mg2+对黑色素几乎无影响;Al3+、Fe2+、Cu2+、pH对多数黑色素色调影响较大,pH值使黑色素色调在酸性和碱性范围内变化分别呈现一定的规律性.  相似文献   

7.
探讨了新型磁性阴离子交换树脂对焦糖色素、类黑色素和葡萄糖碱性降解物等三种色素的交换规律。结果表明 ,磁性树脂对这类色素的交换能力是 :类黑色素 >葡萄糖碱性降解物 >焦糖色素 ,且这种新型树脂对类黑色素和葡萄糖碱性降解物的交换平衡曲线符合 L angm uir方程。  相似文献   

8.
──吴雪辉等,广西蔗糖,1999(2),36~39本文探讨了阴离子交换树脂D201对焦糖色素、类黑色素和葡萄糖碱性降解物等三种精液色素的脱色规律。结果表明:D201树脂的脱色能力是:葡萄糖碱性降解物>类黑色素>焦糖色素。且此树脂对类黑色素和葡萄碱性降解物的交换平衡线符合兰格缨尔方程。阴离子交换树脂对糖液色素脱色规律的研究  相似文献   

9.
以黑色素的提取率为指标,利用果胶酶和纤维素酶,在缓冲液条件下对乌饭树树叶黑色素的提取进行了研究,发现果胶酶和纤维素酶合用有利于提高黑色素的得率,当果胶酶用量为2.5mg/g树叶,纤维素酶用量为3.0mg/g树叶时提取得率超过33mg/g原料.色素稳定性研究结果表明,长时间光照色素颜色加深;酸性条件下色素较稳定;提高温度或延长高温时间可以增强色素显色;Mg2+、Na+、K+、Ca2+、Zn2+对色素影响不大,但是Cu2+和Fe3+对乌饭树树叶黑色素的稳定性影响很大,所以在黑色素保藏和应用中避免接触.  相似文献   

10.
从膨化玉米黄粉中提取的天然黄色素是一种安全无毒的食用色素。文中主要研究了该色素的稳定性以及食品中常用的几种食品添加剂对该色素稳定性的影响。结果表明:该色素耐光性较差,有一定的耐热性,食用植物油对其有很好的保护作用,对Al~(3+)、Fe~(3+)、Cu~(2+)等离子极不稳定,对高浓度的氧化剂稳定性较差而对酸、碱、还原剂、含氧酸根、Fe~(2+)、Na~+、K~+等较稳定;其中,木糖醇对该色素有一定的保护作用,V_C和香兰素对该色素也有较强的保护作用,且香兰素的保护作用要明显优于V_C的保护作用。  相似文献   

11.
Melanin derived from Osmanthus fragrans’ seeds was isolated from O. fragrans’ seeds by alkaline extraction, acid hydrolysis, and repeated precipitation with a yield of 0.34 g/100 g (wet weight basis). Physical and chemical properties of the melanin revealed that the melanin derived directly from O. fragrans’ seeds were similar to typical melanin. The melanin was stable under ultraviolet light or room-light, stable in the range of 25-100 °C, relatively stable in alkaline solution, reducer and salt, but was bleached by strong oxidants (KMnO4, K2Cr2O7 and NaOCl). The metal-ion of Ca2+, Cu2+, Fe3+ and Zn2+ had the function of color increase or color preservation to the melanin. Although Mg2+, Al3+ and Na+ reduce pigment color, it was not obvious. Amino acid and organic acid did not affect the melanin, while sugar, starch, and glucose affected it slightly.  相似文献   

12.
山杏种皮黑色素理化性质研究   总被引:1,自引:0,他引:1  
山杏种皮黑色素具有黑色素典型的性质。稳定性研究表明:温度影响该黑色素的氧化还原状态,但对溶液的颜色无显著影响;pH<6时,冷冻使黑色素沉淀;光照使溶液褪色;随pH升高,溶液颜色略有加深;Na_2SO_3、Ca~(2+)、Cu~(2+)和Zn~(2+)有一定的增色护色作用,Al~(3+)、Mg~(2+)、Na~+、氨基酸、糖和淀粉对该黑色素无显著影响;有机酸使溶液略有褪色。本研究尝试以吸光度的对数对波长的回归直线斜率作为衡量黑色素稳定性的指标,该指标能够很好地反映出山杏种皮黑色素结构的改变。  相似文献   

13.
根据溶解性不同,将栗子壳色素分级得到3种色素组分Fr.1、Fr.2和Fr.3。Fr.1只溶于碱性水溶液;Fr.2溶于碱性水溶液和亲水性有机溶剂;Fr.3在任何pH值的水溶液中都能溶解,在亲水性有机溶剂中也能溶解。对栗子壳色素各分级组分进行了化学定性分析和紫外-可见光光谱分析,并研究了它们的稳定性。各分级组分均具有酚类物质的性质,但不具有黄酮类化合物的典型性质,也不具有鞣性。3种栗子壳色素组分的紫外-可见光光谱都是随着波长增大而吸光度逐渐减小的曲线,在可见光区没有明显的吸收峰,仅在270 nm左右有一肩峰。3种色素组分的溶液颜色均随着pH值的增大而逐渐加深,Fr.1对加热和紫外线相对稳定,而Fr.3最为敏感。氧化剂可使栗子壳色素褪色,且Fr.1褪色幅度最大,Fr.2最小。各色素组分均对还原剂、蔗糖、Na+、Mg2+稳定而对Al3+、Ca2+、Fe2+、Fe3+、Cu2+和Zn2+的稳定性较差。  相似文献   

14.
Cinnamomum burmannii is cultivated for use as a spice, and as an ornamental tree. With the aim to develop a natural colorant for use in cosmetics and food additives from a new source, in the present study, pigment derived from C. burmannii' peel (CBP) was isolated by alkaline extraction, acid hydrolysis, repeated precipitation and purification by Sephadex G-75 with a total yield of 0.06 g/100 g (wet weight basis). The color values of the pigment was E1 cm1% 278 nm = 65.21. Physical and chemical properties revealed that CBP presses similar properties as most natural pigment. It was scarcely soluble in both water and all common organic solvents, and was soluble only in alkaline aqueous and DMSO. It was stable under ultraviolet light or room-light, stable in the range of 25-100 °C, relatively stable in alkaline aqueous and reducer, but was bleached by strong oxidants (KMnO4, H2O2 and NaOCl). Sodium benzoic acid, tartaric acid, table salt and cane sugar affected it slightly. Spectroscopic analysis of CBP in relation with its structure was also discussed. This is the first report on the characterization of pigment obtained from C. burmannii 'peel.  相似文献   

15.
Melanins are pigments of high molecular weight formed by oxidative polymerization of phenolic or indolic compounds. In this present study, a black pigment was isolated from the fermentation broth of Ophiocordyceps sinensis, an entomogenous fungus which is endemic to the Tibetan Plateau by alkaline extraction, acid hydrolysis, and repeated precipitation. It was designed as melanin since the physical and chemical properties including its ultraviolet (UV) and infrared (IR) spectra of the black pigment conformed to the characteristic of melanin and similar to the commercial synthetic melanin. The antioxidant activity of melanin derived from O. sinensis was evaluated. They showed much stronger scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl (DPPH•) and the chelating ability on ferrous ions than that of the water extract from the mycelia of O. sinensis, with IC50 value 18.51 ± 0.85 μg/ml and 2.58 ± 0.26 μg/ml, separately. This is the first report of melanin from O. sinensis and will be helpful for the study on the physiology and the artificial cultivation of this fungus, an endangered species.  相似文献   

16.
以碱性溶液为提取剂,运用单因素试验及响应面法对马铃薯液态培养基培养冠突散囊菌(Eurotium cristatum)所产的胞外黑色素的提取工艺条件进行优化,得到最优提取条件。单因素试验以NaOH溶液浓度、提取温度、色素酸沉pH值和料液比(发酵液∶NaOH溶液)为评价因素,黑色素提取量为响应值,并在此基础上建立4因素3水平响应面试验。结果表明,冠突散囊菌胞外黑色素的最佳提取工艺参数为:NaOH浓度1 mol/L,提取温度74 ℃,色素酸沉pH值2.5,料液比为1∶1.4(V∶V)。在该优化条件下,提取的黑色素含量最高,为3.982 mg/mL。  相似文献   

17.
分别采用红色和黑色两种颜色高粱壳为原料提取高粱红色素,对其理化性质分析比较,可知黑壳色素提取率为5.2%,色价45,耐热性能好,色调为紫褐色,色泽较暗;红壳色素提取率为3.1%,色价32,色调为红棕色,色泽较亮。  相似文献   

18.
A novel red pigment (RP) was isolated from Osmanthus fragrans  ’ seeds. The optimised experimental parameters of extraction obtained with a four-factor at three-level orthogonal array experimental design L9(34)L9(34) were ethanol concentration, temperature, pH and extraction time as 90%, 78 °C, 2.5 and 40 min, respectively. A yield of 34.6 ± 2.2 g/100 g was obtained under optimised conditions. The red pigment directly from O. fragrans’ seeds can be dissolved in alkaline, acidic waters solutions and hydrophilic organic solvents in common use. The colour of a water solution of RP changed with pH. RP was stable to heat in the temperature range of 25–100 °C. Physical and chemical properties of RP revealed that the red pigment was also stable in the presence of Na2SO3, NaCl, amino acid, organic acid, sugar, starch or metal-ions (such as Ca2+, Cu2+, Fe3+, Zn2+, Al3+, Mg2+ and Na+), but was bleached by strong oxidants (KMnO4, K2Cr2O7 and NaOCl). Subsequently, free radical scavenging activities of RP were assessed using 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals using a new resonance scattering spectral method. RP showed an excellent DPPH radical scavenging activity and was superior to butylated hydroxytoluene (BHT), and exhibited quite a strong concentration-dependent inhibition of hydroxyl radical at low concentrations compared with ascorbic acid and quercetin. When the concentration of RP was 0.03 μg/ml, the scavenging percentage of hydroxyl radical reached 92.3%. Salidroside was isolated as an active principle.  相似文献   

19.
板栗壳棕色素的提取及其相关性质研究   总被引:1,自引:0,他引:1  
以乙醇作溶剂,用一次浸提法从板栗壳中提取天然棕色素.正交试验结果表明:提取时间2.5 h、浸提温度75℃、乙醇浓度40%、固液比1:20(g:mL)时,棕色素的提取率较高,为5.52%.对相关性质进行测定表明:所得棕色素溶于水、乙醇、甲醇,不溶于苯、丙酮、乙酸乙酯等溶液;PH值对棕色素影响不明显;棕色素水溶液有较好的耐光性耐热性及较好的抗氧化性抗还原性;金属离子Ca2+、Mg2+、Zn2+、Ba2+、Na+、K+对色素的颜色无明显影响,但金属离子Fe3+、Pb2+、Cu2+会与色素反应生成沉淀并褪色.  相似文献   

20.
以紫红豇豆为原料,研究了豆荚与种子中紫红色素理化性质以及防腐剂、pH值、光照、温度、还原剂、氧化剂和7种常见金属离子对其稳定性的影响,旨在为紫红豇豆色素的提取加工及工业应用提供理论依据。结果显示:豆荚与种子的紫红色素在紫外区的最大吸收波长分别为270nm和207nm,在可见区的最大吸收波长分别为542nm和481nm,紫红色素水溶性好,颜色随pH值变化而变化(pH<3时颜色鲜红;pH>7时,颜色由紫色转为绿色)。酸性条件(pH<)下该色素对光、低温有很好的稳定性,耐氧化性与耐还原性较强。Ca2+、Na+、Mg2+、K+、Zn2+等离子对紫红色素的稳定性影响不大,Cu2+、Fe3+离子使色素稳定性变差。  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