Synergistic frozen storage-thermal processing drives tilapia muscle quality deterioration via protein structural transitions and regulation

This study elucidates the synergistic deterioration of tilapia muscle quality during frozen storage (0-120 days) and thermal processing (3-9 min), identifying critical thresholds for quality preservation. Prolonged freezing (>60 days) and extended heating (>5 min) synergistically amplified texture loss, umami depletion, and protein structural damage (α-helix disruption, β-sheet gain), exceeding additive effects. Short heating (≤5 min) mitigated freeze-induced texture degradation and preserved umami dominance, while extended heating triggered irreversible protein aggregation and bitterness. Mechanistically, ice-crystal-induced myofibrillar weakening during freezing was amplified by thermal processing, accelerating hydrophobic exposure and matrix collapse. These findings establish ≤60-day storage and ≤5-min heating as pivotal thresholds to optimize frozen aquatic product processing, offering actionable guidelines for industrial quality control.