Abstract
<jats:p xml:lang="en">Chicory roots (Cichorium intybus L.) are rich in phenolic compounds with strong antioxidant activity, making them valuable for functional food and nutraceutical applications. This study optimized ultrasound-assisted extraction (UAE) of bioactive compounds from dried chicory roots using an acidified hydroethanolic solvent system (80% ethanol containing 1% HCl, v/v) and a Box–Behnken design. Ultrasound amplitude (60–80%), extraction time (3–7 min), and solid-to-liquid ratio (5–15%) were evaluated for their effects on total phenolic content (TPC) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. ANOVA indicated that all linear factors significantly affected antioxidant activity (p ≤ 0.05), with solid-to-liquid ratio contributing 71.58% of total variability. For TPC, amplitude and time were significant, while concentration showed a marginal effect. Interaction effects, particularly between amplitude and concentration, were notable. Optimal conditions were 74.85% amplitude, 15% concentration, and 3 min, yielding 133.79 ± 4.43 mg GAE/100 g TPC and 61.06 ± 3.36% DPPH inhibition. UAE proved to be a rapid and efficient method for enhancing phenolic recovery.</jats:p>