Modeling and Optimization of phenolic compound extraction from licorice root by microwave assisted method

In present study, response surface methodology was used to optimize extraction condition of phenolic compounds from licorice root by microwave application. Investigated factors were solvent (ethanol 80%, methanol 80% and water), liquid/solid ratio (10:1, 17.5:1, 25:1) and time (2, 4 and 6min). Experiments were designed according to the central composite rotatable design. The results showed that extraction conditions had significant effect on the extraction yield of phenolic compounds and antioxidant capacities. Optimal condition in microwave assisted method were ethanol80% as solvent, extraction time of 5-6 min and liquid/solid ratio of 16.5/1. Amount of phenolic compounds and extraction yield of licorice root in microwave assisted (MAE), were 47.43 mg/g and 16.38%, respectively. The antioxidant activity of optimal extract was assessed by DPPH, reducing power and total antioxidant capacity assay and results were compared with synthetic antioxidant BHT.