Characterizing the proteomic and mitochondrial functional differences between normal-pH and dark-cutting beef

Dark-cutting beef is an example of color deviation, in which beef fails to have a characteristic bright-red color. The overall goal of the current research was to determine the biochemical basis of dark-cutting beef. Two separate experiments were conducted to determine differential protein expression and mitochondrial functional differences between normal-pH and dark-cutting beef. Protein profiles were identified using proteomic analysis and mitochondrial respiration function was evaluated using a Clark-oxygen electrode. Mass spectrometry analysis identified 1,162 proteins. Of these, 92 proteins were differentially expressed (p 0.05) in mitochondrial complexes I and IV respiration, state IV oxygen consumption and mitochondrial membrane integrity from normal-pH and dark-cutting beef. The results from the current study suggest that a greater expression of mitochondrial electron transport chain proteins supports mitochondrial respiratory function in dark-cutting beef, which can influence color development and stability via oxygen consumption. Understanding the biochemical basis will help to elucidate the etiology of the dark-cutting phenotype