Heat stress induces various oxidative damages to myofibrillar proteins in ducks.

A high-temperature environment was simulated to investigate the effects of heat stress (HS) on duck myofibrillar proteins (MPs). Compared to the control (25 °C), antemortem HS (32 °C) accelerated MP oxidation, as the contents of carbonyl and total/active sulfhydryl significantly increased. HS-induced oxidation changed MP secondary structures, and enhanced MP aggregation and surface hydrophobicity. MP digestibility was lowered for both gastric and intestinal digestions, and depletion of an essential amino acid (His) was observed, indicating nutritional loss. HS induced a sharp loss of the MP storage modulus (G') during gelation, accompanied by gel with weaker elasticity, hardness, strength, and water retention, which implicated the low quality of relevant meat products. Potential specific correlations of amino acids and structural changes with MP and MP-gel properties were also explored. The results reveal that antemortem HS causes adverse effects on duck meat quality and nutrition, and may contribute to its recognition and prevention.