Optimization of the extraction of phenolic compounds from the leaves of yerba mate (Ilex paraguariensis) through high hydrostatic pressure system using mixture design with process variables

In this study, a mixture design with process variables was used to optimize the extraction of total phenolic compounds (TPC) from yerba mate leaves through high hydrostatic pressure extraction. The studied variables were pressure (50, 100, and 150 MPa), extraction time (10, 20, and 30 min), and solvent (water, glycerin, and 50% v/vwater/50% v/v glycerin). The multiple linear regression model presented an excellent fit (R-2 adjusted of 0.9792) and demonstrated the major influence of glycerin content on the water/glycerinmixture solvent for TPC extraction. Optimal process conditions obtainedwere 69% v/vwater, 31% v/v glycerin, 50 MPa pressure, and 10 min time.