Resistant Starch Dynamics in Whole‐Grain Cereals: How Processing and Macromolecular Interactions Shape Quality and Physiological Responses

Abstract

Resistant starch (RS) in whole‐grain cereals is not a fixed ingredient attribute but a dynamic and structure‐dependent fraction shaped by grain microstructure and processing–storage histories. This review synthesizes evidence on how thermal, mechanical, and biochemical treatments in whole‐grain matrices remodel starch supramolecular organization and drive interconversion among RS1–RS5. Emphasis is placed on matrix constraints imposed by bran cell walls, proteins, endogenous lipids, and dietary fiber, which redistribute water, modulate gelatinization and retrogradation, and control enzyme accessibility through encapsulation and diffusion barriers. We integrate mechanistic pathways, including granule disruption and re‐association, amylose/amylopectin retrogradation (RS3), amylose–lipid complexation (RS5), and cell‐wall‐mediated physical protection (RS1), and relate these multiscale structural changes to digestion kinetics, glycemic responses, colonic fermentation potential, and to product‐level attributes such as texture and storage stability in whole‐grain foods. Finally, we identify priorities for translating RS dynamics into predictable product design: standardized multiscale structural characterization, explicit reporting of whole‐grain matrix features, and validation in intact whole‐grain foods under realistic processing and dietary conditions.