Mechanistic insights into gluten network alteration in Rumex hanus-fortified steamed bread: From molecular interactions to quality characteristics

Steamed bread is a common staple with good taste and digestibility but low nutritional value. <i>Rumex hanus by.</i> (RHB) is rich in protein, fiber, and minerals, making it a promising fortifier. This study examined the effects of 0-10% RHB addition on the nutritional quality, texture, and gluten structure of steamed bread. RHB significantly increased protein, fiber, amino acids, and minerals but, at levels ≥4%, reduced sensory quality due to texture deterioration. Mechanistic analysis showed that RHB lowered gluten zeta potential, inhibited disulfide bond formation, and caused glutenin depolymerization, leading to smaller particles, reduced hydrophobicity, and more disordered protein structures. These changes weakened the gluten network, reducing dough elasticity and gas retention. Consequently, the specific volume decreased by 25.29%, and hardness rose by 217.05%. This work offers guidance for optimizing nutrition and quality in functional steamed bread.