Ultrahigh magnetic field pretreatment modulates starch-rich matrix remodeling and germination in oat seeds.

Ultrahigh magnetic fields (UMF, 1-15 T) can modulate seed germination, but their intensity-dependent effects on the starch structure within the native seed matrix remain unclear. In this study, oat seeds were exposed to ultra-high magnetic fields, and analyses were conducted directly on whole-grain oat flour to preserve the authentic starch-lipid-protein microenvironment. Multi-scale structural characterization revealed two distinct, starch-centered remodeling pathways regulated by magnetic field strength. A moderate 5 T magnetic field enhanced double-helix stacking and increased relative crystallinity (10.56%), thereby inhibiting excessive starch hydrolysis and preserving the highest starch content (58.45%) while maintaining a high germination rate (93.68%). In contrast, an extreme 15 T magnetic field resulted in granule fragmentation, and the leaching of starch and hydrophobic substances, thereby achieving the highest germination rate (98.05%). The migration of surface hydrophobic substances further synergized with starch remodeling by modulating the hydrophobic barrier and enzyme accessibility. These findings confirm that UMF is a non-contact physical strategy capable of enhancing germination rates by remodeling the structure of whole oat flour through adjustment of UMF intensity, providing new insights into seed pre-treatment and the regulation of carbohydrate polymers.