Antioxidant activity and physicochemical kinetics of a compounded spirit infused with <i>Calophyllum brasiliense</i> seeds

The rising demand for alcoholic beverages with functional properties and distinct sensory profiles has driven innovation in the use of bioactive plant materials. This study investigated the antioxidant activity and physicochemical behavior of a compounded spirit infused with Calophyllum brasiliense (guanandi) seeds an agro-industrial by-product rich in phenolic compounds. Infusions were prepared using hydroalcoholic solutions at two ethanol concentrations (38° and 50° GL), as well as a gradual dilution protocol, and monitored over 27 days at 48-h intervals. Significant variations were observed in pH, titratable acidity, density, dry extract, and total soluble solids. Beverages prepared with 38° GL exhibited higher titratable acidity and density, while those at 50° GL showed greater pH and dry extract values. Antioxidant activity assessed by DPPH, ABTS, and FRAP assays revealed formulation-dependent variability. A strong positive correlation was found between total phenolic content (TPC) and FRAP values (ρ = 0.755), and an inverse correlation between alcohol strength and DPPH activity (ρ = −0.721). Four formulations were selected based on regulatory compliance, physicochemical performance, and sensory potential, demonstrating antioxidant capacities comparable to fruit-based liqueurs and highlighting the suitability of C. brasiliense seeds for functional spirit development.