High pressure processing of glutinous rice starch complexed with Buddleja officinalis Maxim. Extract: Structural...

This study investigated the impact of high pressure processing (HPP) on yellow glutinous rice starch (Y-GRS) formed by glutinous rice starch (GRS) complexed with Buddleja officinalis Maxim. extract (BOME). Y-GRS at 500 MPa achieved the highest complex index (0.506), indicating stronger starch-BOME interactions. Particle size analysis revealed that Y-GRS exhibited superior resistance to swelling, with D[4,3] increasing by 18.97 μm for Y-GRS and 31.64 μm for GRS as the pressure increased from 400 to 600 MPa. Y-GRS retained higher thermal stability, with an enthalpy change of 1.55 J/g at 500 MPa, compared with 0.83 J/g for GRS. The relative crystallinity of Y-GRS was 8.81 % higher than that of GRS. Structural analyses confirmed BOME mitigated higher pressure-induced damage to starch granule, preserving double helix and crystal structure. Rheologically, Y-GRS exhibited stable peak viscosity, weaker shear thinning behavior, and greater resistance to deformation than GRS. Following HPP, Y-GRS contained lower levels of rapidly digestible starch (RDS) and higher levels of resistant starch (RS) than GRS. In conclusion, these findings highlight HPP as a promising strategy for enhancing the functional properties of Y-GRS, offering improved stability and digestibility for starch-based food applications.