Underlying connections between the redox system imbalance, protein oxidation and impaired quality traits in pale, soft and exudative (PSE) poultry meat

The connections between the redox imbalance in post-mortem muscle, early protein oxidation and the onset of pale, soft and exudative (PSE) condition in chicken breast are studied. PSE was induced by incubation of post-mortem chicken carcasses at 37°C for 200min. PSE-induced muscle consistently had faster pH decline and lower pH at 200min (5.84 vs. 6.59) and 24h (5.69 vs. 5.96), higher L(∗) (54.4 vs. 57.3), and lower texture and water holding capacity (WHC) than normal meat. The activities of catalase, glutathione peroxidase and superoxide dismutase were significantly lower in PSE-induced samples than in the normal counterparts. PSE was more susceptible to proteolysis and protein oxidation than normal meat during succeeding chilled storage with more intense tryptophan and thiols depletion, higher protein carbonylation and more intense formation of protein cross-links. We provide plausible explanations to support the role of protein oxidation in the impaired quality PSE chicken.