Beyond waste to bioactive potential: advances in olive by-product valorization and resource recovery

The olive oil industry produces millions of tons of underutilized by-products, including pomace, leaves, and wastewater, which pose significant environmental and economic challenges. These residues, however, are rich in bioactive compounds like polyphenols, proteins, and pectin, offering substantial potential for high-value applications in food, pharmaceuticals, and cosmetics. This review provides a comprehensive overview of the compositional profiles, valorization strategies, and technological barriers associated with olive by-products. It critically examines advancements in green extraction methods and bioconversion technologies, while addressing limitations in multi-component separation, bioactive compound stabilization, and scalability. The review highlights the need for integrated biorefinery systems, AI-driven optimization, and standardized validation frameworks to overcome these challenges. Furthermore, it emphasizes the transition from traditional waste management to circular economy models and underscores the importance of cross-sectoral collaboration in aligning olive by-product valorization with global sustainability objectives, advancing both scientific research and resource efficiency.