Enhanced Extraction of Polyphenols, Flavonoids and Antioxidant Activity from Cynometra ananta Stem Bark using Ultrasonic Method: A Kinetic Modelling Approach

Cynometra ananta stem bark is rich in bioactive phenolic compounds with antioxidant potential. This study evaluated the efficiency of ultrasound-assisted extraction (UAE) in comparison to conventional maceration at various solid-to-liquid ratios (1:60, 1:80, and 1:120 g/mL) and described the extraction kinetics using a second-order kinetic equation. The highest polyphenol yield was achieved with UAE at a 1/60 ratio (482 µg GAE/mg DM), surpassing maceration (420 µg GAE/mg DM). Flavonoid content also increased significantly with UAE, reaching 14.18 µg QE/mg DM versus 7.72 μg QE/mg DM with maceration. Antioxidant activity (FRAP) was enhanced by ultrasound, with a saturation concentration of 238 µg Trolox/mg DM. Kinetic modeling showed excellent correlation (R2 > 0.99) across all conditions. The improved performance of UAE is attributed to enhanced mass transfer, solvent penetration and cavitation effects. These findings highlight ultrasound-assisted extraction as a powerful, cost-effective method for recovering polyphenols and flavonoids from C. ananta, with promising implications for natural antioxidant production.