Optimized Extraction of Phenolic Compounds from Ficus exasperata Using Ultrasound and Maceration: A Comparative Kinetic Study

Ficus exasperata is a medicinal plant used in West Africa for managing inflammation, infections, and oxidative stress. However, its optimized extraction processes remain poorly studied. Conventional maceration (MAC) and ultrasound-assisted extraction (ULT) were compared for phenol and flavonoid recovery from F. exasperata leaves at solid-to-liquid ratios of 1/60, 1/80, and 1/120 g/mL. Extraction yields were measured over 35 minutes and fitted to a second-order kinetic model. ULT markedly increased yields, especially at 1/60 g/mL, achieving 351.5 mg GAE/g DM (phenolic compounds) and 8.88 mg QE/g DM (flavonoids). The model showed excellent fit (R² > 0.99) and indicated internal diffusion as the rate-limiting step. Higher kinetic constants under ULT confirmed its faster extraction rate. ULT outperformed MAC, making it a more efficient and sustainable green technology for producing antioxidant-rich extracts while enhancing the mechanistic understanding of plant-based solid–liquid extraction.