不同花色杜鹃花色素成分与稳定性分析研究

目的]全面分析不同花色杜鹃花的色素成分与稳定性。方法]以4种不同花色的杜鹃花花瓣(浅红、紫色、白色和粉红色)为试材,对其花色素提取液进行紫外-可见光光谱扫描检测、特征显色反应和稳定性分析。结果]试验表明,杜鹃不同花色色素不含叶绿素和类胡萝卜素;粉色、浅红色和紫色杜鹃花色素主要由花色素苷和类黄酮化合物组成;白色杜鹃花色素则含非红色的类黄酮化合物以及其他化合物,其花色素不具备邻二酚羟基或邻三酚羟基结构,揭示了杜鹃花色呈现差异的内在本质。紫外-可见光光谱扫描的结果表明,不同花色素溶液中的花色素种类与含量不同。稳定性研究表明,食品添加剂、低价金属离子对色素色泽无不良影响,但碱性环境、氧化还原剂以及Fe3+、Al3+均对其稳定性影响较大,探明了有利于杜鹃花色素稳定的环境条件。结论]研究可为杜鹃花色素的分离鉴定奠定基础,同时也为天然杜鹃花色素的科学利用提供理论依据。

Analysis on Components and Stability of Anthocyanidin from Rhododendron with Different Color

Objective ] To fully analyze the components and stability of anthocyanidin from Rhododendron with different color. Method ] Four kinds of azaleas petal with different color （white, pink, light red and purple Rhododendron） were used to investigate the anthocyanidin compo- nent and its stability using UV - visible spectroscopy technique and characteristic color reaction. Result] The results indicated that there is no chlorophyll and carotenoids in the pigment extracts of azaleas. The flower-pigment extracts of pink, light red and purple Rhododendron composed principally of anthocyanins and flavonoids. There are only some non red flavonoids and some other compounds in the extracts of white flower, and it has no structure of pyrocatechol hydroxylation and pyrogallol hydroxylation. These results indicated the essence of flower color was that there were different flower pigments types and different chemical characteristics. According to the absorption spectrum analysis on these four kinds of pigments, the results showed that the types and content of flower pigments is different in the azaleas petal with different color. Further experi- ments in vitro showed that the food additives and low valence metal ions had no negative effect on the stability of pigments in Rhododendron. However, the stability of pigments in Rhododendron was significant affected by alkaline environment, oxidants, and Fe3~ and A13~ metal ions. Conclusion] These results will provide some very important information for further isolation and identification of pigments in Rhododendron and application of natural pigment in Rhododendron.