Extraction of epigallocatechin gallate from green tea via modified supercritical CO2: Experimental, modeling and optimization

In this study, modeling of epigallocatechin gallate (EGCG) extraction from green tea via supercritical carbon dioxide with ethanol as an entrainer was developed. The modeling is based on the differential mass balance between the solid and supercritical (SC) phases. The model was solved numerically and was successfully validated with experimental data. The effects of main extraction variables such as pressure, temperature, CO2 flow rate and dynamic time were investigated on the extraction recovery via the validated model. In addition, effective extraction variables were optimized with genetic algorithm in order to achieve maximum extraction recovery. The optimal values were obtained to be 19.79 MPa, 41.2 °C, 1.7 mL/min and 116.3 min (dynamic extraction time) to achieve 0.447 as the EGCG extraction recovery.