Extraction，physical and chemical properties ofColeus blumei red pigment

In order to comprehend the physical and chemical properties and application feasibility of Coleus blumeipigment，the red pigment was extracted by using acetone as extracting solution，then the physical and chemical propertieswere studied. It was indicated that the maximal absorption wavelength of the pigment was 400 nm，There was noabsorption peak in infrared region. The red color was the deepest at pH 8.0. The pigment was stable at 45℃ to 65℃.When the pigment was heated at 85℃，its color deepened in a short time（within 2 hours）. The pigment was degradedwhen being treated at 85℃ for a long time. White light could make the pigment color darker obviously. The oxidantsodium benzoate could keep the color or had hyperchromic effect on the pigment. The reductant sodium sulfite had stronghyperchromic effect on the pigment. Hydrogen peroxide treatment had hypochromic effect on the pigment. Glucose hadno effect on the color of the pigment. Mg+2 and Na+ had slight hyperchromic effect on the pigment. Ca+2 and K+ in lowconcentration had hyperchromic effect，but Ca+2 and K+ in high concentration had hypochromic effect.