Valorization Pathways of Sweet-Potato Residues: Integrated Strategies for Nutritional Enhancement, Processing Innovation, and Multifield Applications

This review systematically explores the valorization pathways for sweet potato residue (SPR) within the context of a circular bioeconomy. Through an in-depth analysis of the chemical composition of SPR, we elucidated the structural characteristics and functional correlations of its starch-dietary fiber (DF) matrix, identifying the highly insoluble dietary fiber (IDF) content as the primary bottleneck for its direct utilization. This study critically evaluated the roles of physical, chemical, biological, and hybrid modification technologies in deconstructing biomass recalcitrance and tailoring its functional properties. Furthermore, we discuss the current applications of modified SPR in functional food additives, pharmaceutical excipients, biodegradable packaging materials, environmental adsorbents, and bioenergy. An integrated valorization framework linking composition to application was established, along with a critical assessment of systemic barriers to industrial scaling, including logistical costs, environmental footprints, and regulatory challenges. Finally, this review advocates a product-oriented precision transformation strategy, providing a theoretical foundation and practical reference for transitioning SPR from an agricultural byproduct to a sustainable industrial feedstock.