Drying-induced structural reorganization modulates the cooking quality and microrheological behavior of multigrain reconstituted rice.

UNLABELLED: Multigrain reconstituted rice was prepared from quinoa (Chenopodium quinoa Willd.), oat (Avena sativa L.), buckwheat (Fagopyrum esculentum Moench) and millet (Setaria italica L.) flours by single-screw extrusion. Hot-air drying parameters were optimized using single-factor and response surface methodology and the effects of natural drying, hot-air drying, cold-air drying, microwave drying and freeze-drying on product quality were compared. The condition optimized for minimizing cooking loss under hot-air drying was 50 °C for 7 h at a material thickness of 2.5 cm. Microwave drying resulted in the lowest cooking loss, whereas natural drying produced the highest water absorption capacity. Hot-air drying increased gelatinization temperature, indicating improved thermal stability, while cold-air and hot-air showed similarly high crystalline ordering and microrheological stability. Freeze-dried samples showed the highest hardness, adhesiveness, springiness and chewiness. These results indicate that drying methods regulate cooking quality mainly by altering water migration, starch molecular ordering and porous microstructure. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at https://doi.org/10.1007/s10068-026-02256-z.