[Correlation Analysis of Curcuminoids and Color Index L* , a* and b* of Curcumae Longae Rhizoma Powder].

Objective: To study the relationship between the component content of curcuminoids in Curcumae Longae Rhizoma and powder color indeces L*, a* and b* those were measured by chromaticity instrument, in order to provide scientific basis for quality assessment of Curcuma longa medicinal materials.

Methods: Detect the content of curcumin,demethoxycurcumin,bisdemethoxycurcumin,then detect the content of curcuminoids by the Chinese Pharmacopoeia method. Measure the color indeces L*, a* and b* of Curcumae Longae Rhizoma powder by colorimeter. Finally, the relationship between the content and the color was analyzed by using the Grey Relational Analysis, Pearson correlation coefficient and regression analysis.

Results: There was positive correlation between the content of curcuminoids and a*. But there was no definitely relation between the content of curcuminoids and b* or L*.

Conclusion: The content of curcuminoids is closely related with the degree of the color red, the higher the content, the red is deeper. a* could be recognized as an important basis of Curcumae Longae Rhizoma medicinal materials quality.