Supercritical CO_2 Extraction of Flavonoids from the Aerial Parts of Chinese Licorice (Glycyrrhiza uralensis Fisch.)

Factors of effect on the yield of flavonoids from licorice of overground stem and leaves were studied by single factor's analysis experiments.The single factor's analysis experiments were carried out to investigate influential factors of extraction temperature,pressure,flux of CO2 and extraction time.The extraction of flavonoids with Supercritical CO2 was studied on the yield of extracts.It had been found that the optimized technological parameters were: particle size 40～60 sieve mesh,80% ethanol as entrainer,extraction time 1.5 h,extraction pressure 30 MPa,extraction temperature 50℃,CO2 flow rate 10 kg·h-1,separation pressure 5.8 MPa,separation temperature 40℃.The yield of flavonoids was 2.09% and the content was 5.42%.The results offered basic research of a new method for the product of flavonoids of licorice.