Kinetics of aqueous extraction of phenolic compounds from processed yerba mate leaves

In this study, the kinetics of aqueous extraction of phenolic compounds from the yerba mate leaves were analyzed. A temperature range between 40°C and 70°C and a ratio of 25 g of mate leaves in 200 mL of water were used. The extraction kinetic was studied adjustment of the kinetics models of first order, second order kinetic model and the second order diffusive model. The goodness of the fit was controlled by the magnitude of the coefficient of determination (R2), the percentage error (EP %) and the square root of the mean square error (RMSE).The second order kinetic models adequately described the extraction process, achieving the best fit with the second order diffusive model (EP%= 0,81 to 2,9; EP%= 11,24 to 14,99 and 4,72 and 6,92) that provided important information about the initial extraction process and the mechanism that occurs in the final extraction stage. The temperature influenced the kinetic parameters; however, the final equilibrium concentration of phenolic compounds was not affected by it. The results of this study allow us to obtain better overall knowledge of the times and temperatures for improved extraction rates and energy consumption for the industrialization of these compounds.