NEW INSIGHTS INTO BEEF QUALITY DEVELOPMENT

Define the biochemistry responsible for atypical "dark-cutting" beef.The working hypothesis is that cattle fed low energy diets produce muscle with more oxidative metabolism, which alters postmortem energy metabolism and subsequent color development, independent of animal stress. Determine the role of mitochondrial proteases on postmortem proteolysis and meat tenderness.The working hypothesis is that mitochondria and(or) associated structures modulate proteolysis through an as yet unknown mechanism.Define the biochemical and cellular differences among dark beef and determine the biochemistry responsible for its altered postmortem metabolism.The working hypothesis is that changes in mitochondria impact postmortem metabolism either directly through pH declines or indirectly via associated changes in muscle proteins.