Protein-starch interaction in encapsulation systems: From functional group distribution to physicochemical and...

Protein-starch complexes are increasingly applied in the food and related industries as encapsulation matrices, such as pharmaceuticals and nutraceuticals, for their ability to stabilize, protect, improving bioavailability and enabling controlled release of sensitive bioactive compounds, thereby enhancing product shelf-life, sensory attributes, and nutritional value. This review provides a comprehensive overview of the physicochemical foundations, molecular interactions (based on molecular dynamics simulations), and functional group distribution of protein-starch complexes, with emphasis on their application as wall materials in delivery systems. Subsequently, the review highlights key physicochemical, thermal, and release behaviors of protein-starch-based delivery systems. Finally, it outlines emerging strategies in controlled design, release modulation, and matrix engineering as promising solutions for developing next-generation carriers of bioactive compounds. Protein-starch interactions significantly influence solubility, thermal stability, emulsification properties, retrogradation behavior at a complex formation level, and the physiochemical properties (particle size, surface charge and morphology, and interface properties) and encapsulation efficiency of bioactive compounds. These biopolymeric matrices show strong potential for stimuli-responsive (pH and enzyme) and site-specific release in the gastrointestinal tract. Future research should emphasize hybrid systems, responsive architectures, and AI-based wall material formulations to enhance the stability and functionality of encapsulated nutraceuticals.