Extraction and stability of the pigment from Argyreia acuta Lour

Extraction of the pigment from Argyreia acuta Lour.and its stability were studied in this paper to provide important raw material for all kinds of new pigments used in food products,cosmetic and leechdom,etc.Water was used as extractant during the extraction for 24 h,and the pigment stability was vestigated by UV spectrum.The results showed that the λmax for the pigment was 330 nm,which has good solubility and excellent thermal stability within wide temperate range in water;the alkaline substance has a little effect on the stability of pigment;citric acid,acetic acid and soluble starch had hyperchromic effect on the pigment;some common food additives,such as sodium benzoate,sucrose,glucose had little effect on the stability of the pigment;oxidizing agent,reducing agent,except ascorbic acid,and metallic ions,except Co2+、Fe3+ also had little effect on the stability of the pigment.At the same time,