Solubility of catechin and epicatechin from Arachis Hypogea skins wastes by using supercritical carbon dioxide-ethanol and its optimization

This research aims to optimize a supercritical carbon dioxide extraction assisted by co-solvent ethanol for the recovery of catechin and epicatechin from peanut (Arachis Hypogea) skin. The second objective was to determine the solubility of catechin and epicatechin by semi-empirical models. The operating conditions were: pressure of 10 to 30 MPa; temperature of 313 to 343 K; and ethanol rate of 0.075 to 0.225 mL/min. Response surface methodology (RSM) was applied to determine the optimum condition to recover the catechin and epicatechin. The optimum condition was found to be 21.86 MPa, 332.23 K, and 0.17 mL/min with 752.03 µg/g of catechin and 3399.84 µg/g of epicatechin. Putra model successfully fitted the solubility of catechin and epicatechin in range of 1.21 E-5 g/L and 6.02 E-5 g/L with 3.11% of AARD (%). Application of RSM was succesful to optimize the conditions with high quantity of catechin and epicatechin.