Rapid post-mortem glycolysis and delay chilling of turkey carcasses cause alterations to protein extractability and degradation of breast muscle proteins

SDS-PAGE banding patterns of myofibrillar protein samples from turkey breas t muscle with pH less than or equal to 5.8 at 15 min post-mortem (rapid gly colyzing) contained 133, 142, and 165 kDa bands that were absent in samples from carcasses with pH >6.0 at 15 min post-mortem (normal glycolyzing). Th ese extra protein bands contained fragments of myosin as identified by West ern blot analysis. Myosin fragments were also observed in protein samples f rom breast muscle not allowed to cool until 110 min post-mortem (delay chil led). In addition to myosin degradation, neublin degradation was more exten sive in samples from rapid glycolyzing carcasses than for normal controls. Creatine kinase and glycogen phosphorylase were present in myofibrillar pro tein extracts of rapid glycolyzing carcasses in higher quantities than in n ormal controls. Results of this study provide insight into the molecular ba sis for previously reported reductions in meat quality of rapid glycolyzing and delay chilled turkey meat.