Molecular hydrogen mitigates hydroxyl radical-driven oxidative deterioration of tilapia myofibrillar proteins: through the lens of redox microenvironment modulation

Hydroxyl radical (·OH)-driven oxidation of myofibrillar proteins (MPs) contributes to quality deterioration in refrigerated fish, yet storage-referenced mitigation strategies remain limited. Herein, we established a storage-referenced oxidation framework for tilapia MPs by carbonyl-based equivalence fitting a Fenton-type ·OH-generating system and carbonyl accumulation in vacuum-packaged tilapia muscle during extended refrigerated storage at 4 °C. Within this framework, weeks 1, 4, 6, and 7 corresponded to 20, 50, 80, and 90 mM H₂O₂, respectively, with a maximum absolute prediction error of 8.6%, and 90 mM H₂O₂ was selected as the representative high-oxidation condition. Under this condition, H₂ shifted the system toward a more reducing redox status and reduced the detectable DMPO-OH signal to 24.56% of the 90 mM H₂O₂ control, accompanied by marker-dependent protection against oxidative modification, antioxidant-related readout loss, colloidal destabilization, and secondary-structure deterioration. These findings provide a mechanistic basis for H₂-based reductive preservation of aquatic muscle foods.