Physical and Chemical Properties of Tradescantia Reflexa red Pigment

Objective:To provide important raw material for all kinds of new pigment used in food products,cosmetic and leechdom etc.Study on the stability of red pigment from Tradescantia reflexa and the condition of extraction.Methods: Ethanol was used as the extractant in the extraction,and the pigment stability was investigated by UV spectrum.The optimum condition for ethanol extraction is: distilled water was used as the extractant and it was extracted under room temperature for 24 h.Conclusion:Thelmax for the pigment was 540 nm,which has good solubility in water,and excellent stability in the extractant(pH 3～13) for wide temperature scope,bad light resistance characteritics was observed,however.Some common food additive,such as sodium benzoate,citrate,cane sugar,glucose,oxidizing agent,reducing agent and metallic ions have no effect on its stability.