Hamid Rajabi, Samineh Sedaghati
The global food system generates substantial agricultural by-products (ABPs), which are often underutilized despite being rich sources of bioactive compounds (BACs) with antioxidant, antimicrobial, and anti-inflammatory properties. However, the practical application of these compounds is limited by poor bioavailability, chemical instability, and degradation during processing and digestion. This review examines encapsulation and co-encapsulation technologies as enabling strategies for transforming ABPs into stable, bioavailable functional ingredients. Various encapsulation approaches are discussed in terms of their ability to protect BACs, improve delivery efficiency, and enable controlled release in food systems. Co-encapsulation strategies are highlighted for their potential to create synergistic health effects through the combined delivery of multiple bioactives. The incorporation of encapsulated ABP-derived BACs into functional foods demonstrates their capacity to enhance nutritional quality while reducing reliance on synthetic additives, supporting circular economy principles. Despite these advances, challenges related to scalability, regulatory approval, and consumer acceptance remain. Overall, encapsulation technologies provide a promising pathway for converting low-value agricultural residues into high-value functional resources, contributing to sustainable nutrition and resilient food systems.