Study on stability of red rice red pigment

The stability of red rice red pigment under different conditions such as pH, temperature, exposure time, carboxylic acid-modification, metal ions was investigated by UV-Vis spectrophotometric method. The results showed that the red rice red pigment was stable when the pH was 2~4; temperature, exposure time, carboxylic acid-modification and alkaline condition had effect on its stability; Mg2+, Al3+and Zn2+had little effect on the spectral waveform of red rice red pigment, and Fe3+affected both its waveform and color.