Consumers associate bright-red lean of beef with freshness and wholesomeness. Discoloration of meat has resulted in an annual loss of $1 billion to the US meat industry. In postmortem muscle, mitochondria remain active and can influence beef color by two important biochemical processes such as oxygen consumption (related bloom) and metmyoglobin reduction (related to minimizing brown color). Enzymes involved in glycolysis and tricarboxylic acid cycle can generate reducing equivalents such as succinate or reduced nicotinamide adenine dinucleotide to influence beef color. Moderate mitochondrial activity is critical to have steaks that are bright cherry-red and to have longer color stability. However, various pre- and post-harvest factors can impact mitochondrial activity. The current presentation will focus on the role of interactions between mitochondria, myoglobin, and metabolites in fresh beef color stability. More specifically on how metabolite and mitochondrial interaction can affect bloom and muscle-specific differences in color stability. Recent research our laboratory has utilized metabolomics techniques to characterize the metabolite profile differences between normal and dark-cutting beef. The results suggest that dark-cutting beef has fewer metabolites and greater mitochondrial concentration. The ability of the heme to undergo reduction and/or oxygen binding ability is dependent on amino acid composition. Traditional spectrophotometric techniques will not allow characterizing ligand binding or heme reduction properties. Hence, electrochemistry approach was utilized to investigate the changes in the microenvironment to the atomic level of heme and at the active site. In summary, biomolecular interactions between myoglobin, mitochondria, and metabolites can influence fresh meat color.

Biomolecular interactions between myoglobin, mitochondria, and metabolites governing fresh meat color

2019 Fall National Meeting

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