Two-stage heating strategy modulates protein conformation, water distribution, and sensory quality in roasted...

This study systematically evaluated a two-stage heating strategy incorporating steaming, boiling, or microwave preconditioning on protein properties, water distribution, texture, flavor, and digestibility of roasted crayfish (Procambarus clarkii). Results demonstrated that preconditioning methods critically modulated protein conformational changes and water states, thereby governing final quality attributes. While direct roasting (control) exhibited the lowest carbonyl content (5.99 μmol/kg) but the highest disulfide bond formation (0.27 μmol/g), steam-roasting effectively minimized protein oxidation (0.19 μmol/g disulfide bonds) and promoted controlled unfolding, as reflected by increased surface hydrophobicity. Moist-heat preconditioning, particularly steam-roasting, significantly enhanced water retention, achieving the highest water-holding capacity (86.51%). Steam-roasting also optimized textural properties through balanced hardness and springiness. Flavor analysis revealed that steam-roasting yielded the highest furans content (0.026 μg/g) and total volatile compounds (5.50 μg/g), whereas boil-roasting enriched umami amino acids. The superior in vitro protein digestibility of steam-roasting group was closely associated with reduced protein aggregation. Collectively, the two-stage heating strategy, especially steam preconditioning, synergistically improved sensory and nutritional quality by precisely regulating protein-water interactions and Maillard reaction pathways, providing an effective approach for premium roasted crayfish production.