Pressurized liquid extraction as a strategy to recover bioactive compounds from yerba mate (Ilex paraguariensis St.-Hil.) processing waste

The production process of the yerba mate creates a relevant waste quantity, which is reused in different ways. However, these approaches do not value this material's bioactive compounds. To obtain a valuable extract from yerba mate waste, we used pressurized liquid extraction (PLE) with distilled water as solvent considering different conditions of temperature, solvent flow rate, pressure, static extraction time, and sample particle size. To evaluate the biological properties of the extracts, we measured the total phenolic content (TPC) and chemical composition, besides analyzing their antioxidant activity. The best TPC result (1256.18 mg(GAE)center dot 100 g(YMW)(-1)) was reached at 120 degrees C, 9 mL.min(-1), and 10 MPa. Temperature significantly influenced all extracts' biological characteristics, especially the phenolic content. Our analyses revealed that the PLE technique is a viable approach for obtaining extracts with good biological properties. These results can guide the yerba mate industries to develop higher added-value products from a residue.