The cryoprotective effect of wheat bran-soluble dietary fiber on frozen gluten protein quality

Abstract

This study aimed to investigate the cryoprotective effects of wheat bran-soluble dietary fiber (WB-SDF) on the structural and functional stability of gluten proteins in frozen dough, addressing the limited research on the role of soluble dietary fiber in mitigating freeze-induced quality deterioration. Existing studies predominantly utilized whole dietary fibers, while WB-SDF, with superior hydration and functional properties, holds potential for enhancing frozen dough quality. Gluten protein samples were prepared with varying WB-SDF concentrations (0–8 %), subjected to frozen storage (−20 °C) for 0–60 days, and analyzed for hydration properties, surface hydrophobicity, secondary structure, disulfide bonds, molecular interactions, water distribution, and microstructure. Results demonstrated that 4 % WB-SDF addition optimally preserved gluten protein integrity. Compared with the control group, it significantly enhanced hydration and foaming capabilities, suppressed hydrophobic exposure, mitigated β-turn loss, and reinforced intermolecular forces by stabilizing hydrogen bonding and hydrophobic interactions. SDS-PAGE and SEM confirmed that 4 % WB-SDF promoted protein aggregation and stabilized the gluten network. These findings highlight WB-SDF as an effective cryoprotectant for frozen dough, facilitating high-value utilization of wheat bran and advancing whole wheat product development.