Application of Ultrasound and Natural Deep Eutectic Solvent for the Extraction of Glycyrrhizic Acid from Glycyrrhiza glabra: Optimization and Kinetic Evaluation

Nowadays, natural deep eutectic solvents (NADESs) are regarded as a green and sustainable substitute to traditional organic solvents for the extraction of bioactive molecules. Similarly, ultrasound-assisted extraction (UAE) is an extensively acknowledged environment-friendly technique due to reduced solvent consumption and extraction time as well as enhanced extraction efficiency as compared to conventional techniques. Therefore, the present study investigated the combination of NADES as a green solvent with modern extraction technique such as ultrasound to improve the extraction efficiency of glycyrrhizic acid (GA) from licorice (Glycyrrhiza glabra). The yield of 55.11 mg/g GA was achieved using an ultrasonic probe with 2.66 W/cm(3) acoustic density, 50% duty cycle, 30:1 mL/g liquid to solid ratio, and 30% aqueous choline chloride lactic acid NADES in 15 min. In comparison with the NADES stirred batch extraction method, the NADES-UAE technique reduced the extraction time by 50% and solvent consumption by 25%, offering a high extraction yield of GA. Additionally, the study performed kinetic modeling, and the experimental results were fitted well to a two-site kinetic model.