红汁乳菇色素稳定性的研究

本文对红汁乳菇色素的稳定性进行了系统研究 ,结果表明 :红汁乳菇色素紫外光谱最大吸收波长为 2 5 1nm ,且为单一吸收峰 ;在碱性条件下能稳定存在 ,在酸性条件下随酸度增大吸光度减小 ,颜色变浅 ,稳定性较差 ;对自然光比较敏感 ,耐热性差 ;色素对Fe3 + 较为敏感 ,而Na+ 、K+ 、Ca2 + 、Zn2 + 、Al3 + 、Mg2 + 、Cu2 + 对色素无不良影响 ;色素耐氧化、还原能力较好 ;加入淀粉会使色素增色 ,而葡萄糖、蔗糖、柠檬酸对色素影响甚微     

红凤菜红色素水溶液的稳定性试验

从红凤菜（Gynura bicolor DC.）地上部分提取了红色素水溶液。在350－700nm范围内的扫描结果显示,该色素有2个吸收峰,位于543nm和598nm附近。在pH2.2-6.0的范围内色素较稳定。加热使其吸收峰值增大,但波长基本不变。0.2mmol/L Fe^3 引起色素溶液变色并产生大量沉淀;Al^3 也能使其产生沉淀;Cu^2 对该色素的影响较小;Zn^2 、对其无影响。氧化剂（H2O2）与还原剂（Na2SO3）均能使该色素褪色。光照对该色素无明显影响。     

紫薇花红色素的提取及稳定性的研究

采用正交试验对紫薇花红色素的最佳提取条件进行研究,并探讨该色素的稳定性。结果表明,乙醇浓度40%,料液比1:40(g/mL),提取时间90 min。该色素属水溶性色素,耐室内自然光,热稳定性好;在酸性条件下稳定;金属离子Na+、K+、Mg2+对紫薇花色素基本无影响,而Ca2+、Zn2+、Al3+、Cu2+、Pb2+、Fe2+离子对色素有明显影响。     

三种天然果蔬色素稳定性研究

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。     

金属离子对黑米花青苷色素吸收光谱的影响

以黑糯B糙米皮为实验材料 ,用 1 .5mol/L盐酸— 95 %乙醇 (V/V :1 5 / 85 )溶液提取黑米花青苷色素(BRAP) ,采用紫外可见分光光度法研究了 1 1种金属离子以及 (NH4 ) 1+ 离子对BRAP的作用。结果表明 ,未加离子条件下色素溶液可见光区λmax5 35nm ,紫外光区λmax2 80nm ,加入Al3 + 、Fe3 + 、Fe2 + 、Cu2 + 、Mn2 + 、Zn2 + 、Sn2 + 对其吸收光谱有显性影响。其中Al3 + 、Fe3 + 使 5 35nm特征吸收峰发生蓝移 ,Sn2 + 使其发生明显红移 ;Al3 + ,Fe2 + ,Mn2 + ,Zn2 +在 5 35nm附近有增加ABS值作用 ,Fe3 + 有减小ABS值作用 ;延长作用时间 ,Cu2 + 对BRAP吸收光谱的影响表现为λmax5 35nm发生蓝移 ,ABS值减小     

草莓果实红色素理化特性的研究

本文研究了草莓（Ｆｒａｇａｒｉａ×ａｎａｎａｓｓａＤｕｃｈ．）果实红色素的可见吸收光谱、光稳定性、热稳定性、耐氧化还原性、耐糖性以及金属离子、ｐＨ的变化对色素的影响。结果表明,草莓果实红色素的提取方法简单易行,色素性质优良。该色素具有广阔的开发应用前景。     

红龙草红色素稳定性的研究

分析了pH值、温度、光、过氰化氢、亚硫酸钠、Vc、葡萄糖、蔗糖和苯甲酸钠等对红龙草（Altemanthera dentate ‘Ruliginosa’）红色素稳定性的影响。结果表明,红龙草红色素对热的耐受性较强,但耐光照和耐氧化性较差,且还原剂亚硫酸钠对其也有微弱的影响;在不同的pH值条件下,其吸收峰没有改变,最大吸收波长为530nm;Vc和蔗糖对该色素没有破坏作用,并有一定的护色效果;葡萄糖和苯甲酸钠对该色素也无明显影响。     

酶法合成黑色素的稳定性研究

运用紫外分光光度计对以酪氨酸为底物酶法合成的黑色素进行稳定性分析,结果表明:该黑色素的最大吸收峰为212 nm,不溶于水和酸,易溶于碱,在碱性条件下颜色稳定。热、自然光、紫外光、蔗糖、葡萄糖对色素稳定性无影响;氧化剂H2O2和还原剂Na2SO3对其影响不大;几种金属离子(除Fe2+)对黑色素吸光值及颜色无影响。     

天然落葵红色素稳定性实验研究

从落葵科落葵属植物落葵(Basella rubra L.)成熟果实中提制的落葵红色素,其着色力极好,在pH3—7范围内呈较鲜艳的紫红色。光照、加热和Fe~(2 )。Fe~(3 )、Cu~(2 )等金属离子的加入,有使该色素受到破坏的趋势。当添加适量的抗坏血酸后其光稳定性可以得到改善。     

阿魏酸和水杨酸对枣皮红色素理化性质的影响

以枣(Jujube)皮为原料,经酶解和微波超声波处理后提取红色素,研究酰基化剂(Acylating agent)对红色素理化性质的影响.结果显示,枣皮红色素分别与阿魏酸和水杨酸形成的复合物对光和部分金属如Na+、Ca2+和Fe3+稳定;在pH 1～7范围内不稳定,pH 9～14范围内稳定.结果表明,阿魏酸和水杨酸与枣皮红色素复合后产生的酰基化产物有助于红色素分子的稳定.     

Variations in the spectrum of desulfoviridin from Desulfovibrio gigas.

Desulfoviridin preparations from D. gigas showed variations in the position of the absorption maximum the beta-peak) in the 580-nm region of the specturm. On treatment with Na2S2O4 a preparation with a beta-peak at 585 nm was affected rapidly, the 585-nm peak shifting to the 596-nm region; this was partially reversed by K3Fe(CN)6. Treatment of the original preparation with K3Fe(CN)6 resulted in a shift of the beta-peak to 582-583 nm. Desulfoviridins with beta-peaks from 580 to 583 nm were not rapidly affected by Na2S2O4. The spectrum of the chromophore of desulfoviridin way also affected by Na2S2O4 with the peak at 587 nm shifting to 597 nm; this effect was completely reversed by oxygen. There was no evidence to show that spectral variations in desulfoviridin preparations were due to the loss or acquisition of metal ions during growth or to the selection of mutants containing spectrally different desulfoviridins. It is suggested that during biosynethesis oal detachment of the chromophore, thus causing a change towards the spectral properites of the detached chromophore.     

红穗醋栗色素理化性质的研究

本试验研究了红穗醋栗色素的理化性质,结果表明:红穗醋栗色素热稳定性很好,而光照对其有一定的降解作用。pH值对该色素影响明显,宜在酸性食品中应用。几种金属离子Na~ 、Ca~(2 )、Al~(3 )、Zn~(2 )。Cu~(2 )对该色素的色泽没有影响;而Fe~(3 )、Sn~(2 )则有不良影响。食品中常含的几种添加物葡萄糖、蔗糖、淀粉和抗坏血酸对该色素无不良影响。红穗醋栗色素对Na_2SO_3的还原性耐性较强,对H_2O_2的耐氧化性很差。防腐剂苯甲酸钠对该色素也有一定的不良影响。     

蛹虫草菌丝体水溶性黄色素组分分析及其稳定性研究

本研究以蛹虫草菌丝体为供试材料,采用高效液相色谱对提取的蛹虫草菌丝体水溶性黄色素的组分进行了分离纯化与测定分析,并以其主要组分YP-4为检测指标,采用温度、光照、pH、金属离子、常见食品添加剂等条件对蛹虫草菌丝体水溶性黄色素稳定性的影响进行了较为系统的研究。结果表明,蛹虫草菌丝体水溶性黄色素由5种结构相似的类胡萝卜素组分组成。其中,主要组分YP-4占到WSYPs总量的57.43%,YP-4的MS data [M-H]为521.2657,紫外特征吸收峰为：209nm、239nm、421nm、445nm、474nm,在445nm处有最大吸收峰。以YP-4为检测指标,对提取蛹虫草菌丝体黄色素的稳定性测试结果表明,该类黄色素具有良好的加工稳定性,但在加工过程中应尽量缩减紫外光照射时间,注意酸性添加剂和Fe ³⁺的用量。这一研究结果将为蛹虫草菌丝体水溶性黄色素乃至其他优质天然黄色素的开发利用提供参考依据。     

多花野牡丹红色素的提取及其稳定性研究

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,Fe3+、Cu2+、Mn2+、Zn2+对色素有明显降解作用,而Na+、Mg2+、Al3+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。     

高粱叶片磷酸烯醇式丙酮酸羧化酶溶液构象状态的紫外差示吸收光谱研究

PEP诱导产生的差光谱在237nm是一强负峰,在252nm附近呈宽负峰。Mg~(2+)产生的差光谱在275nm附近为正的阔峰,在237nm处为一负峰。PEP、Mg~(2+)共同与酶作用的差光谱在263nm附近呈宽的负峰。正效应剂G6P、Gly及GG分别存在条件下PEP羧化酶的差光谱亦各具明显差异,在270nm以下光区内尤其显著。在284nm和291nm为两个负峰,Gly诱导的峰强度大于G6P的,而GG复合效应剂对此两峰的影响表现很大的协同作用。Mal作用于酶的差光谱在246nm处有一负峰。     

Analyses of absorption and fluorescence spectra of water-soluble chlorophyll proteins, pigment system II particles and chlorophyll a in diethylether solution by the curve-fitting method.

Absorption and fluorescence spectra in the red region of water-soluble chlorophyll proteins, Lepidium CP661, CP663 and Brassica CP673, pigment System II particles of spinach chloroplasts and chlorophyll a in diethylether solution at 25 degrees C were analyzed by the curve-fitting method (French, C.S., Brown, J.S. and Lawrence, M.C. (1972) Plant Physiol 49, 421--429). It was found that each of the chlorophyll forms of the chlorophyll proteins and the pigment System II particles had a corresponding fluorescence band with the Stokes shift ranging from 0.6 to 4.0 nm. The absorption spectrum of chlorophyll a in diethylether solution was analyzed to one major band with a peak at 660.5 nm and some minor bands, while the fluorescence spectrum was analyzed to one major band with a peak at 664.9 nm and some minor bands. A mirror image was clearly demonstrated between the resolved spectra of absorption and fluorescence. The absorption spectrum of Lepidium CP661 was composed of a chlorophyll b form with a peak at 652.8 nm and two chlorophyll a forms with peaks at 662.6 and 671.9 nm. The fluorescence spectrum was analyzed to five component bands. Three of them with peaks at 654.8, 664.6 and 674.6 nm were attributed to emissions of the three chlorophyll forms with the Stokes shift of 2.0--2.7 nm. The absorption spectrum of Brassica CP673 had a chlorophyll b form with a peak at 653.7 nm and four chlorophyll a forms with peaks at 662.7, 671.3, 676.9 and 684.2 nm. The fluorescence spectrum was resolved into seven component bands. Four of them with peaks at 666.7, 673.1, 677.5 and 686.2 nm corresponded to the four chlorophyll a forms with the Stokes shift of 0.6--4.0 nm. The absorption spectrum of the pigment System II particles had a chlorophyll b form with a peak at 652.4 nm and three chlorophyll a forms with peaks at 662.9, 672.1 and 681.6 nm. The fluorescence spectrum was analyzed to four major component bands with peaks at 674.1, 682.8, 692.0 and 706.7 nm and some minor bands. The former two bands corresponded to the chlorophyll a forms with peaks at 672.1 and 681.6 nm with the Stokes shift of 2.0 and 1.2 nm, respectively. Absorption spectra at 25 degrees C and at --196 degrees C of the water-soluble chlorophyll proteins were compared by the curve-fitting methods. The component bands at --196 degrees C were blue-shifted by 0.8--4.1 nm and narrower in half widths as compared to those at 25 degrees C.     

Analyses of absorption and fluorescence spectra of water-soluble chlorophyll proteins,pigment System II particles and chlorophyll a in diethylether solution by the curve-fitting method

Absorption and fluorescence spectra in the red region of water-soluble chlorophyll proteins, Lepidium CP661, CP663 and Brassica CP673, pigment System II particles of spinach chloroplasts and chlorophyll a in diethylether solution at 25°C were analyzed by the curve-fitting method (French, C.S., Brown, J.S. and Lawrence, M.C. (1972) Plant Physiol. 49, 421–429). It was found that each of the chlorophyll forms of the chlorophyll proteins and the pigment System II particles had a corresponding fluorescence band with the Stokes shift ranging from 0.6 to 4.0 nm.The absorption spectrum of chlorophyll a in diethylether solution was analyzed to one major band with a peak at 660.5 nm and some minor bands, while the fluorescence spectrum was analyzed to one major band with a peak at 664.9 nm and some minor bands. A mirror image was clearly demonstrated between the resolved spectra of absorption and fluorescence. The absorption spectrum of Lepidium CP661 was composed of a chlorophyll b form with a peak at 652.8 nm and two chlorophyll a forms with peaks at 662.6 and 671.9 nm. The fluorescence spectrum was analyzed to five component bands. Three of them with peaks at 654.8, 664.6 and 674.6 nm were attributed to emissions of the three chlorophyll forms with the Stokes shift of 2.0–2.7 nm. The absorption spectrum of Brassica CP673 had a chlorophyll b form with a peak at 653.7 nm and four chlorophyll a forms with peaks at 662.7, 671.3, 676.9 and 684.2 nm. The fluorescence spectrum was resolved into seven component bands. Four of them with peaks at 666.7, 673.1, 677.5 and 686.2 nm corresponded to the four chlorophyll a forms with the Stokes shift of 0.6–4.0 nm. The absorption spectrum of the pigment System II particles had a chlorophyll b form with a peak at 652.4 nm and three chlorophyll a forms with peaks at 662.9, 672.1 and 681.6 nm. The fluorescence spectrum was analyzed to four major component bands with peaks at 674.1, 682.8, 692.0 and 706.7 nm and some minor bands. The former two bands corresponded to the chlorophyll a forms with peaks at 672.1 and 681.6 nm with the Stokes shift of 2.0 and 1.2 nm, respectively.Absorption spectra at 25°C and at ?196°C of the water-soluble chlorophyll proteins were compared by the curve-fitting method. The component bands at ?196°C were blue-shifted by 0.8–4.1 nm and narrower in half widths as compared to those at 25°C.