Effect of ultimate pH and freezing on the biochemical properties of proteins in turkey breast meat

Biochemical and functional properties of proteins from turkey breast meat with different ultimate pH at 24 h post-mortem (pH24) in fresh and frozen conditions have been studied. Meat with different pH24 was referred to as low, normal and high pH meat. Low and normal pH meat showed similar properties indicating their similarity in the extent of protein denaturation. Total (193 mg/g) and sarcoplasmic (99 mg/g) protein solubilities were significantly (p < 0.0001) higher in high pH meat compared to those of low and normal pH meat, and hence expected to have better functional properties. Freezing caused denaturation and oxidation of proteins as revealed by a significant decrease in Ca2+-ATPase activity (p < 0.0001), total protein solubility (p < 0.0001), reactive (p < 0.05) and total sulphydryl groups (p < 0.0001) and an increase in the formation of carbonyl groups (p < 0.0001), which may have implications for functionality.