铁皮石斛花中花色成分抗氧化性和稳定性研究

Analysis on stability and antioxidant capacity of color-related components from Dendrobium officinale flower

为了阐明铁皮石斛花中花色成分的抗氧化活性及其稳定性,该实验选取10个铁皮石斛家系的花为材料,采用紫外-可见分光光度法测定铁皮石斛全花及唇瓣提取液中的花色苷、类胡萝卜素和类黄酮的含量,以及清除DPPH自由基（DPPH·）,超氧阴离子自由基（·O2-）和羟基自由基（·OH）的能力,并分析Cu2＋,Mg2＋,Al3＋,K＋等金属离子和食品添加剂对铁皮石斛花中花色苷稳定性的影响。结果表明,铁皮石斛花中含有丰富的花色苷,类胡萝卜素和类黄酮等花色相关成分,这些成分在不同家系及不同部位中的分布存在一定差异,其中唇瓣中花色苷（1330.9μg·g-1）含量显著高于全花样本（696.3μg·g-1）,且类胡萝卜素含量与花色苷含量呈显著正相关;铁皮石斛花提取液清除3种自由基的能力都与花色苷含量呈显著正相关,相关系数分别为0.384,0.415,0.455,说明花色苷类成分是铁皮石斛花中主要的抗氧化物质。金属离子Cu2＋,Mg2＋,Al3＋,K＋使铁皮石斛花提取液吸光度增大,具有增色作用;甜味剂葡萄糖对铁皮石斛花中花色苷有护色作用,而抗坏血酸对铁皮石斛花中花色苷有明显的破坏作用。

The study is aimed to fully analyze antioxidant activty and stability of color-related components from Dendrobium officinale flower. The contents of anthocyanins,carotenoids and flavonoids of 10 varieties including whole flower and labellum of D. officinale flower were detected using UV visible spectroscopy technique and evaluated for their 1,1-diphenyl-2-picrylhydrazyl radical（ DPPH·）,superoxide anion radical（ ·O2-） and hydroxy radical（·OH） scavenging activty. And the effects of 4 kinds of metal ions（ Cu2＋,Mg2＋,Al3＋,K＋） and 2 kinds of food additives were investigated on the stability of anthocyanins pigment from D. officinale flower. The results indicated that the flower of D. officinale contained anthocyanins,carotenoids and flavonoids,and their contents in different parts of different families varied. The content of anthocyanins（ 1 330. 9 μg·g-1） in labellum was significantly higher than that in the whole flower（ 696. 3 μg·g-1）. The content of carotenoids was positively correlated with the content of anthocyanins,and there was significant positive correlation between the scavenging capacities of the three free radicals and the contents of anthocyanin,respectively（ 0. 415,0. 384,0. 455）. The Cu2＋,Mg2＋,Al3＋,K＋ and glucose showed significant color-enhancing effect and could increase the stability of anthocyanin in D. officinale flower,while ascorbic acids showed remarkably degradation effect of anthocyanin in D. officinale flower.