不同检测方法分析紫甘薯红色素的抗氧化能力

Antioxidation analysis of red pigment from purple sweet potato by different test methods

采用比色法(分光光度法)、化学发光法、荧光法分析了紫甘薯红色素对体外活性氧(O2-·和·OH)的清除作用和对体外脂质体过氧化产物丙二醛(MDA)生成的抑制作用。结果表明:紫甘薯红色素对邻苯三酚自氧化体系产生的O2-·具有一定的清除作用,但低于对照抗坏血酸(VC),采用化学发光法测定时,这种清除效果强于采用比色法;色素对Fenton反应产生的·OH具有清除作用,采用化学发光法测定时,这种清除效果最好(高于VC),荧光法次之(稍高于VC),比色法最差(高浓度时显著低于VC);对Fe2+-H2O2诱导小鼠肝组织匀浆脂质过氧化产物丙二醛的生成具有抑制作用,采用TBA荧光光度法测定时,这种抑制作用(略低于VC)强于采用TBA比色法(高浓度时显著低于VC)。与比色法相比,化学发光法和荧光法用于分析花色苷类色素抗氧化能力的大小灵敏度高,选择性强,能减少由于花色苷类色素自身在可见光区的光谱吸收对测定结果的干扰。

The scavenging ability on ROS and products of lipid peroxidation of red pigment from purple sweet potato was analysed by means of colorimetry（spectrophotometry）,chemiluminescence,fluorospectrophotometry, in models for generation of superoxide anion, hydroxyl radicals malonaldehyde （MDA）. The results showed that the red pigment had certain scavenging effects on superoxide anion produced by pyrogallol autoxidation system,but lower than L-Ascorbic acid （V_c）,and the scavenging effects determined by chemiluminescence was stronger than colorimetry. The pigment had scavenging effects on hydroxyl free radical produced by Fenton reaction,and the effects determined by chemiluminescence （stronger than V_c） was the strongest,next fluorescence（stronger slightly than V_c）,final colorimetry（Iower evidently than V_c at high concentrations）. The pigment also had inhibitory action on generation of MDA,the production of lipid peroxidation induced by Fe2＋- H202 on rat liver tissue homogenates in vitro,and the action determined by TBA fluorospectrophotometry （Iowerer slightly than V_c） was stronger than TBA colorimetry（Iower evidently than V_c at high concentrations）. Compared with colorimetry,chemiluminescence and fluorescence had high sensitivity and strong selectivity, and overcome the interference from spectral absorption of the pigment at the visible light on the test results.