Solid-liquid extraction of bioactive compounds from yerba mate (Ilex paraguariensis) leaves

Abstract

The aqueous batch extraction of bioactive compounds from yerba mate leaves was evaluated at different temperature (20, 50, 80°C) and stirring (0, 200, 400 rpm) conditions. The chlorogenic acid (5-CQA) and caffeine (Ca) concentration over time was evaluated by two mathematical models (equilibrium-dependent and intra-particle diffusion). The kinetics data show that the extraction process approached the equilibrium about 120-180 min. The equilibrium-dependent model presented the worse quality of model adjustment. The model derived from Fick’s second law was found to be more suitable to describing the kinetics indicating that is the diffusion intra-particle stage that controls the extraction rates. The diffusion coefficients varied from 1.07x10-4 to 7.91x10-4 mm²min-1 to 5-CQA and from 1.18x10-4 to 8.22x10-4 mm²min-1 to Ca, where higher values are obtained at higher temperatures.