Integrated COSMO-RS modeling and experimental approach for solvent selection, bioactive recovery and anthocyanin stability from Ilex paraguariensis A.St.-Hil. fruits

Abstract Yerba mate ( Ilex paraguariensis A.St.-Hil.) fruits are underutilized despite their high valorization potential. To address this, the fruits were characterized, phenolic and anthocyanin extraction was optimized, and pigment thermal stability was evaluated. The fruits exhibited high carbohydrate (51.74 ± 0.48 g/100 g), dietary fiber (23.10 ± 0.35 g/100 g), and protein (6.56 ± 0.26 g/100 g) contents. COSMO-RS simulations and a Central Composite Design (CCD) identified 45% acidified ethanol at 90 °C as the optimal extraction condition. Under these conditions, the extract presented 16.00 ± 0.49 g/kg of total phenolics, 469.37 ± 24.36 mg/kg of anthocyanins, and high antioxidant capacities (58.35, 45.61, and 28.43 mmol TE/kg for DPPH, ABTS, and FRAP, respectively). The phenolic profile revealed a predominance of caffeoylquinic acids (particularly neochlorogenic acid), rutin, cyanidin-3-glucoside, and delphinidin-3-O-glucoside. Anthocyanin stability was strongly influenced by pH and temperature, generally following first-order degradation kinetics. Pigments were highly stable at pH 1.0 within the 60–75 °C range but underwent significant degradation at higher pH levels and 90 °C. These findings highlight yerba mate fruits as a sustainable source of bioactive compounds, encouraging their valorization as natural ingredients for functional foods and technological applications.