A multivariate optimization approach to developing a coffee pulp infusion with maximized phenolic compounds, caffeine, and antioxidant properties, applying a validated UHPLC method

Coffee pulp (CP) may provide a sustainable functional infusion, being a promising alternative for its valorization. This study optimized CP infusion for maximum phenolic compounds, caffeine, and antioxidant properties, using a three-factor, three-level response surface experimental design by MODDE® 13 software. Particle size, solid/liquid (S/L) ratio, and infusion time modifications influenced the concentration of bioactive compounds and antioxidant activities, with the S/L ratio as the most influential. The optimal infusion (0.2–1 mm as particle size, 0.08 g mL −1 as S/L ratio, and 9 min as infusion time) exhibited 1504.2 µg GAE mL −1 of total phenolic compounds, 153.1 µg mL −1 of protocatechuic acid, 169.0 µg mL −1 of chlorogenic acid, 509.2 µg mL −1 of caffeine, and 2913.5 µg TE mL −1 of ABTS antioxidant activity. This optimized CP infusion offers a sustainable, antioxidant-rich beverage with potential health benefits. • Validation of a reliable UHPLC-PDA-QDA method for quantifying bioactive compounds. • Solid-liquid ratio was the most influential parameter in the infusion bioactivity. • Reduced particle size produced infusions with higher antioxidant capacity. • Longer infusion time promoted the release of bioactive compounds. • Optimal infusion: 0.2–1 mm particle size, 0.08 g/mL ratio, 9 min infusion time.