Advancements in food waste valorization through ultrasound-assisted extraction: A review

Abstract

The increasing global issue of food waste (FW) presents significant ecological and financial burdens, with approximately 30 % of worldwide food production discarded annually. This substantial volume necessitates innovative approaches to minimize its environmental impact and unlock its inherent value. While conventional extraction methods often suffer from high energy consumption, long processing times, and reliance on hazardous solvents, this review centers on Ultrasound-Assisted Extraction (UAE) as a pivotal green technology for the sustainable recovery of valuable bioactive compounds from diverse FW streams. UAE utilizes acoustic cavitation to improve extraction efficiency, leading to faster processes, reduced energy consumption, and often allowing for environmentally friendly solvents. This study systematically examines recent advancements (2015–2025) in UAE's application across various FW categories, including fruit and vegetable residues, cereal by-products, and other industrial discards. The paper explores current optimization strategies, the integration of innovative green solvents like natural deep eutectic solvents, and the comprehensive characterization of extracted compounds for their functional properties. The potential of these extracts in functional foods, cosmetics, and pharmaceuticals is highlighted. Finally, critical future research avenues are identified, including industrial scaling, thorough techno-economic and life cycle assessments, advanced solvent recovery, and integrated biorefinery concepts. This review aims to consolidate knowledge, accelerating FW transformation into valuable resources for a more circular and sustainable economy.