Effect of ultra-high pressure (UHP) treatment on structural properties and processing characteristics of oat dough

Abstract

This study investigated the effects of ultra-high pressure (UHP, 100–500 MPa) on the structural and processing properties of oat dough. Amino acid content remained stable at 0–400 MPa but significantly decreased at 500 MPa (P < 0.05). Structural analyses (XRD, FT-IR, microscopy) revealed progressive starch modifications: 100–300 MPa induced surface morphological changes, reduced starch swelling, and improved pasting resistance. At 500 MPa, starch granules lost their ellipsoidal shapes, formed honeycomb-like surfaces, and exhibited disrupted crystallinity (reduced XRD peaks), correlating with increased gelation and water absorption. These structural changes influenced processing performance, particularly at 500 MPa, which significantly increased the hardness and chewiness of oat dough. Pressures of ≥500 MPa induced irreversible and synergistic transformations, including complete loss of starch crystallinity, formation of a honeycomb-like protein-starch gel matrix, and a concurrent increase in water absorption capacity and texture hardening. This work provides theoretical insights for oat food processing.