Abstract: The extraction conditions and physical-chemical properties of the pigment from Kang-xian flower were studied. Polar solvent such as ethonal, methonal and water were proved to effectively extract the pigment of Kang-xian flower. The most effective solvent to extract the pigment of Kang-xian flower was ethonal-water (60:40, volume ratio). The absorption peaks of the pigment from Kang-xian flower appeared at 220 nm and 260 nm by UV. The color of the pigment of Kang-xian was red at the pH 1-4, but it was faded as the pH value increased. It turned to yellow-green color when the pH value was over 7. The stability of the pigment of Kang-xian flower was good with the light and hot by pH 1 and the temperature was under 60℃. Cu²⁺ and Fe³⁺ had great influences on color and stability of the pigment. The food additive Vc also could decrease the stability of the pigment. Relative to the anti-oxidation,the anti-reduction ability of the pigment of Kang-xian flower was seemed more superior.

Key words: Kang-xian flower, physical-chemical properties, pigment