Abstract
Wheat milling efficiency and flour quality are fundamentally governed by kernel fracture behavior during mechanical processing. This study systematically investigated the fracture characteristics of wheat kernels through a multi-stage experimental approach. Rupture tests comparing shear and compression loading revealed that shear reduced fracture energy by 40%, with vitreous kernels (16.13 mJ) showing greater resistance than floury types (10.45 mJ) at 13% moisture. Microstructural characterization revealed distinct fracture modes: vitreous kernels fractured intercellularly, while floury kernels fractured intracellularly-quantified via fractal geometry (vitreous: fractal dimension D = 1.262; floury: D = 1.365). Controlled bran removal experiments demonstrated that outer bran layers provide 40% of total fracture resistance, with vitreous kernels depending primarily on endosperm properties beyond 5% peeling, whereas floury kernels exhibited progressive strength loss with each layer removed. These findings enable optimized milling strategies: shear-based systems for energy efficiency, minimal processing (≤5% bran removal) for vitreous wheat, and moderate peeling (≤10%) for floury wheat, ultimately advancing both scientific understanding and industrial practice in cereal processing.