Modified starch-based carriers for bioactive compound delivery: advances in modification strategies, release mechanisms, and functional performance

ABSTARCTStarch-based delivery systems (SBDSs) have emerged as promising carriers for bioactive compounds (BCs) due to their biodegradability, low cost, and biocompatibility. However, the limited emulsifying capacity, poor physicochemical stability, and rapid digestibility of native starches restrict their applications. Yet critical gaps persist in understanding how starch modifications impact digestibility, release kinetics, and functional performance. This review critically evaluates how the modifications induce changes in molecular structure and supramolecular structure, which influence the encapsulation efficiency (EE), gastrointestinal (GI) release, and stability of BCs. A unified structure-property-function framework is provided by integrating parameters such as crystallinity, cross-link density, amphiphilicity, and digestibility fractions, including rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS), with digestion behavior, release mechanisms, and bioaccessibility. The review further highlights emerging concepts such as digestion-tailored carrier engineering and synergistic dual-modification approaches. Additionally, it addresses key translation challenges, including clean-label requirements, regulatory constraints, scalability, process complexity, and inconsistencies between in vitro and in vivo performance. Overall, this review provides mechanistic and translation insights for designing advanced starch-based carriers with improved controlled-release performance and practical applicability.