Study on extraction and characterization of red pigment from Hibiscus syriacus L.

Physico-chemical properties and extractions of the red pigment in flowers of Hibiscus syriacus L.were investigated.Results showed that good yield of pigment could be obtained by 95% C_(2)H_(5)OH solution(with 10% HCl) of pH 1 at 80℃ for 60min with the solid-liquid ratio 1∶30 g/mL.The Hibiscus syriacus L.red pigment is classified to anthocyanins,for which pH had significant effect on the tone of pigment.The pigment is suitable to acid environment while its good heat resistance.Under sunlight,degradation of the pigment could be accelerated.Metallic ions Na~(+),Ca~(2+),Zn~(2+),A1~(3+),Cu~(2+)had no effect on the tone of pigment,but Fe~(3+),Pb~(2+) had severe disadvantageous effect.T 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.