Effect of Ethanol Concentration in Ultrasound Assisted Extraction of Glycyrrhizic Acid From Licorice Root

The major active component in licorice is glycyrrhizic acid which is very useful in thepharmaceutical industry. in the present work, the extraction of glycyrrhizic acid inlicorice is carried out in a stirred reactor as well as under indirect sonication in anultrasonic bath. batch extraction is carried out in a glass reactor of 150 ml capacityequipped with a six bladed glass turbine for agitation. ultrasound assisted extractionhas been carried out in a dual frequency ultrasound cleaning bath. the glycyrrhizicacid is analyzed using hplc. various process parameters such as solventconcentration, power, frequency of ultrasound, extraction temperature and solvent tosolute ratio, which affect the extraction yield are optimized for both techniques. inultrasound assisted extraction with final optimized conditions, i.e. 50% ethanol assolvent, 230 w power, 40:1 solvent to solute ratio, 30?c temperature and 40 khzfrequency, 95.69% extraction is obtained in 20 minutes, whereas in extraction usingstirred reactor only 68% extraction is observed in 60 minutes. kinetic of the extractionprocess is studied and volumetric mass transfer coefficients as well as theoretical yieldfor different process parameters are estimated.