Interaction of rice proteins with flavor compounds: multi-spectroscopic insights and multimodal binding analysis

Flavor compounds with different structures showed distinct binding patterns. • Heat treatment enhanced flavor-protein interaction. • Binding was mainly driven by hydrogen bonding and hydrophobic forces. • Glutelin contributed 65.9% to overall flavor binding. • Docking energies showed protein-dependent correlations with binding behavior. Interactions between rice proteins and flavor compounds play a crucial role in flavor retention and release. This study examined binding mechanisms with five key flavor compounds and the influence of heat treatment. Rice proteins showed relatively strong binding to (E)-2-octenal (45.05%), 1-octen-3-one (22.07%), and 2-pentylfuran (46.63%), which increased after heating, while 1-octen-3-ol (13.03%) and nonanoic acid (19.95%) showed lower binding and were more easily released. Spectroscopic analyses indicated that protein–flavor interactions were mainly driven by static quenching and accompanied by structural changes in rice proteins. Molecular docking suggested hydrogen bonding and hydrophobic interactions as the major contributors, with residues ARG103, THR155, ARG52, and LYS143 in albumin, globulin, prolamin, and glutelin, respectively, contributing to binding specificity. Regression analysis quantified the contributions of storage proteins, highlighting glutelin as the dominant contributor (65.9%). Overall, this study clarifies protein–flavor interaction mechanisms and their heat-induced changes, offering insights for improving rice flavor quality. Download: Download high-res image (258KB) Download: Download full-size image