Nonlinear structural reorganisation of corn starch induced by high-pressure processing regulates its thermal, pasting and hydration behaviour.

This study investigated the impact of high-pressure processing (HPP) on the multi-scale structure, hydration, and pasting properties of corn starch. Corn starch was subjected to pressures ranging from 100 to 600 MPa for holding times of 1 to 5 min. LF-NMR and MRI analyses demonstrated that HPP redistributed water mobility, with a distinct structural reorganisation observed at 200 MPa, characterised by maximum water immobilisation (P2,1 + P2,2 = 3.97%). Thermal analysis via DSC indicated a non-linear shift in the gelatinisation temperatures (To, Tp, Tc), with pressure-reorganised domains exhibiting higher thermal resistance despite a decrease in gelatinisation enthalpy (ΔH). Furthermore, RVA pasting profiles showed that HPP significantly increased pasting temperatures while reducing peak and final viscosities, indicating improved shear stability and suppressed retrogradation. These findings provide a mechanistic framework for using HPP as a precise tool to engineer starch functionality for clean-label food applications.