Study on Anthocyanidin Extraction from Flower of Rhododendron L. and Its Stability

[Objective] The aim of this study was to further investigate and utilize the natural anthocyanidin from Rhododendron L. [Method] Using Rhododendron L. with four different colors including white, pink, red and purple as the test materials, its anthocyanidin extraction methods were analyzed in this study to evaluate the spectral properties and its stability of various anthocyanidin. [Result] The anthocyanidin from Rhododendron L. was perfectly extracted by methanol with 1% concentrated hydrochloric acid (V/V) and had better stability in this extraction solution. The further experiment in vitro indicated that the anthocyanidin from Rhododendron L. became stable with pH value of 0-3, but could not resistant to high temperature or strong light, and the alkaline condition had also great effects on its stability. [Conclusion] The methanol with 1% concentrated hydrochloric acid (V/V) has the best effect for extraction, and the anthocyanidin from Rhododendron L. is more stable in low temperature, weak light and acid conditions.