Ultrasonic extraction of phenolic compounds from Ficus Lutea trunk bark: Impact of solid–liquid ratio

This study examines the ultrasonic recovery of phenolic compounds from Ficus lutea trunk bark, with a particular emphasis on how the solid-to-liquid ratio impacts extraction efficiency. Using ultrasound-assisted extraction (UAE), experiments were conducted under controlled conditions at an extraction temperature of 40 °C, ultrasonic power of 240 kW, and frequency of 40 kHz. The experimental setup varied the solid-to-liquid ratios of 1/120, 1/80, and 1/60 g/mL. Phenolic content was measured as milligram gallic acid equivalents (mg GAE) per gram dry weight (g DW). Results showed that optimal ultrasonic cavitation at the specified temperature and power settings led to improved cell disruption and diffusion, thereby enhancing the release of phenolic compounds. The highest recovery was achieved with a solid-liquid ratio of 1/60 g/mL, yielding a polyphenol content of 385±3 mg GAE/g DW. The second-order kinetic model was applied to study the extraction kinetics and was found to be highly suitable for the process, with an R² ˃ 0.99 and RMSE ˂ 2.14 10⁻³. In summary, the findings underscore the significance of the solid-liquid ratio in the extraction process, offering a foundation for further refinement and scale-up in industrial applications. The environmental benefits of the ultrasonic method, including reduced solvent usage and energy consumption, also promote sustainability.