Objective: To examine the correlation between storage periods and L*, a* and b* color of Moutan Cortex.
Methods: A optical density meter was used for the measurement of reflected light from sieved powder and section samples using the CIE 1976 L~*,a~*,b~* color system. The content of paeonol were determined by HPLC. The correlation between storage periods,paeonol content and color indices of Moutan Cortex was analyzed.
Results: The measured color was significantly correlated with storage periods. The color of Moutan Cortex shift toward the red with the increase of storage periods. The storage periods were correlated with paeonol content. The measured color was equably correlated with paeonol content.
Conclusion: The correlation between the color of Moutan Cortex and storage periods was found in this study. Measurment of the color of Moutan Cortex can be used to appraise its storage periods and quality.