Starch-based food packaging films from fundamental challenges to intelligent applications

Starch-based films offer an eco-friendly alternative to synthetic polymers, providing renewability and compostability. However, challenges such as high hydrophilicity, retrogradation, and performance variability limit their application. This review examines recent advances in starch-based food packaging through a structure-process-property-function framework. Molecular architecture, granule morphology, and botanical origin significantly affect film properties, including tensile strength (TS), flexibility, and barrier performance. Modification strategies, including physical treatments and chemical processes that enhance water resistance, mechanical strength, and stability, were systematically presented, along with functional composites that provide antimicrobial, antioxidant, and spoilage-monitoring capabilities. The review also discusses scaling up from laboratory to industrial applications, emphasizing the need for extrusion-compatible formulations and standardized testing protocols. Economic viability is further supported by starch valorization from agro-industrial by-products. Future research should focus on optimizing multi-functional, multi-stimuli-responsive films for active and smart food packaging, with particular attention to sustainability, processing, and regulatory standards.