Purification and Decolorization of Extracted Glycyrrhizin from Licorice Root for Pharmaceutical Applications

Licorice is a self-propelling plant that has many applications in pharmaceutical and food industries. Glycyrrhiza Glabra is a kind of licorice whose main active component is a triterpenoid saponin named glycyrrhizin. After extraction, acid precipitation used for preliminary isolation and concentration. Flavonoids are found as pigment in the aqueous extracted product. Decolorization of this extract is one of the major problem. Adsorption with activated carbon was used considering operational parameters including pH, temperature and agitation. Finally, decolorized extract was purified by crystallization in aqueous ethanol at different pH and ethanol percentage to yield the final purified product. Results show that the best pH for precipitation is about 2. Norit Activated Carbon is found to be the good choice for adsorption by 64% yield and 68% purity in industry. Crystallization can purify the extract by 90% aqueous ethanol at pH 13 to result in a product of 98.2% purity. In this case, however, the production output decreased to 65%.