The absorption spectrum for the red frangipani extract adsorbed on TiO2 surface shown in Fig. 2 is broader and exhibit a clear red shift of the absorption peak from 530 to 562 nm. This red shift indicates that extracts are well adsorbed onto TiO2 surface and may increase the absorption of light by the TiO2 particles in the visible region due to the binding of anthocyanins present in the extract to the oxide surface