Study on extraction and characterization of red pigment from colocasia esculenla schott

Physico-chemical properties and extractions of the red pigment of Colocasia esculenla Schott were investigated.Results showed that good yield of pigment could be obtained by 20% C_2H_5OH solution of pH1 at 60℃ for 10min with the solid-liquid ratio 1∶20 g/mL.The Colocasia esculenla Schott red pigment is classified to anthocyanins,for which pH had significant effect on the tone of pigment.The pigment is stable to heat under 80℃.Under sunlight,degradation of the pigment could be accelerated,but regardless of ultraviolet light.Metallic ions Na~+、Ca~(2+)、Zn~(2+) 、AL~(3+)had no effect on the tone of pigment,but Cu~(2+)、Fe~(3+)、Pb~(2+) had severe disadvantageous effect.This kind of pigment has better endurance capability against reducing agent,but it has less resistance capability against oxidizing agent.Addition of glucose,sucrose had no effect on the pigment.