Modulating chestnut starch digestibility by heat–moisture synergistic recrystallization treatment: from condition optimization, physical properties to structural aspects

Abstract BACKGROUND With the advent of the health‐conscious era, starch digestibility has emerged as a critical research focus. Heat–moisture synergistic recrystallization treatment (HMRT) was used to modulate starch molecular mobility through controlled thermal energy and moisture input. Based on the rearrangement of starch molecules under physical fields, this study investigated the mechanisms involved in the formation of starch resistance to digestion, thereby providing theoretical support for the application of chestnut starch (CS). RESULTS HMRT conditions were optimized for moisture content (20%), heating temperature (100 °C for 4 h) and recrystallization temperature (4 °C for 4 h), resulting in a resistant starch increase from 42.35% to 58.67%. Additionally, physical characteristics revealed that HMRT reduced CS hydration properties, improved viscoelasticity of gelatinization and enhanced thermal stability from 60.8 to 66.5 °C. Structural analysis confirmed that HMRT augmented double‐helix content, minimized amorphous domains and increased relative crystallinity (by 4.46%) of CS. CONCLUSION HMRT was proven to be an effective strategy for increasing starch resistance. In this study, the crystallinity and orderability of starch were enhanced after HMRT. Furthermore, decreased starch hydration was shown to impede enzymatic digestion. The research sheds new light on the rational design of anti‐digestive starch‐based food systems with tailored properties. © 2026 Society of Chemical Industry.