The photo-stability of curcuminoid was studied,and its solutions were analyzed pre and post light by HPLC.The results showed that curcuminoid in ethanol solution was unstable exposured to sunlight and stable under the conditions of indoor lighting,UV irradiation and dark;Citric acid,BHT and β-CD were less helpful for the stability of curcuminoid;curcuminoid powder was relatively stable.The analysis of HPLC showed that the degradation rates of curcumin,demethoxycurcumin and bisdemethoxycurcumin were 68.9%,51...