Changes in chemical stability and bioactivities of curcumin by ultraviolet radiation

Abstract

Curcumin, a yellow pigment from turmeric (Curcuma longa), has shown various health beneficial effects. In the present study, changes in the chemical stability and bioactivities of curcumin by UV radiation were investigated. Curcumin degradation in water or phosphate buffered saline was accelerated under UV radiation (254 nm); the residual levels of curcumin were 36.9 and 16.8%, respectively, after 24 h radiation. Decomposition of curcumin by UV was more prominent at higher pHs. ABTS radical scavenging activity of curcumin after 24 h radiation was reduced significantly (p 0.05) as compared to those of curcumin stored at a dark place. Stabilities and bioactivities of curcumin powder treated under UV radiation were, however, not significantly changed (p>0.05). The present results suggest that certain processing or storing conditions exposed to UV radiation could affect stability and bioactivities of curcumin.