Abstract
The recovery of bioactive compounds from food waste using green technologies aligns with green chemistry principles. This study compares chlorogenic acid extraction from fennel waste via ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE). The optimal conditions were identified by a Box-Behnken design with a response surface methodology. The results revealed the superior efficiency of MAE, likely because of the high fibre content in the matrix, which hinders UAE cavitation. This research highlights the potential of MAEs for creating bioactive-rich products from fennel waste, contributing to sustainable waste valorization practices.