Solid-liquid extraction of bioactive compounds from yerba mate (Ilex paraguariensis) leaves: Experimental study, kinetics and modeling

The aqueous batch extraction of bioactive compounds from yerba mate leaves was evaluated in view of their potential application in the food industry. The influence of temperature (20-80 degrees C) and stirring (0-400rpm) was investigated by central composite design. The concentrations of the bioactive compounds over time were investigated using three mathematical models (equilibrium-dependent, Peleg and intra-particle diffusion). The results indicated that higher temperatures resulted in increased extraction of the bioactive compounds, while stirring showed only a minor influence. According to the kinetics data, the extraction process approached equilibrium after around 120-180min. The conditions that maximized the extraction were 80 degrees C and 400rpm, which resulted in 591.81, 48.31, 814.90, and 122.56mgL(-1) of chlorogenic acid, rutin, caffeine, and theobromine, respectively, after a 30min process. The Peleg model was found to be the most suitable to describe the extraction process due the best fit with the experimental data. Practical applicationsYerba mate contains bioactive compounds that have the potential to prevent degenerative diseases. Caffeine, theobromine, chlorogenic acid, and rutin are the main compounds found in yerba mate and they have properties which are beneficial to health, such as antioxidant capacity and diuretic action. These compounds can be removed from the leaves by solid-liquid extraction and added to food products to increase their nutraceutical value. The extraction is influenced by several parameters that need to be adjusted to ensure maximum extract yield and quality. Thus, due to the significant potential of yerba mate as a source of bioactive compounds, the aim of this study was to evaluate the extraction of individual bioactive compounds from the leaves.