Study on extraction of red pigment from Gynura bicolor with supercritical CO_2 fluid

Using the supercritical CO2 fluid extraction,red pigment was extracted from Gynura bicolor. The effects of extraction time,temperature,pressure and entrainer dosage on the yield of red pigment were focused on. The results indicated the optimum extraction parameters as entrainer 10%,extraction time 80 min,extraction temperature 45℃ and extraction pressure 20 MPa.