Effect of electron beam irradiation pretreatment on the structure, physicochemical properties, and digestibility of starch-tannic acid complexes

Electron beam irradiation (EBI) is a low-temperature, high-energy, non-thermal process that enables rapid, uniform treatment with minimal residual effects compared to conventional irradiation techniques, making it particularly suitable for modifying sensitive biopolymers like starch and its application in functional food. Our study explored EBI for modifying corn starch (CS) and enhancing its interaction with tannic acid (TA) to form starch–polyphenol complexes. CS was pretreated with EBI at varying doses, and subsequently complexed with TA. The resulting CS–TA complexes were characterized in terms of their multiscale structure, physicochemical properties, and digestibility. At 10 % TA loading, EBI pretreatment promoted CS–TA binding, leading to notable alterations in crystalline order and pasting behavior, particularly at 5 kGy and 20 kGy. While EBI did not visibly alter starch morphology, it significantly improved the thermal stability of CS–TA complexes. Additionally, the in vitro digestibility of the complexes was jointly influenced by the EBI dose and TA concentration. These findings highlight the unique potential of EBI technology for tuning starch–polyphenol interactions, offering a clean and effective approach for designing functional food ingredients with enhanced stability and nutritional properties.