Molecular factors influencing meat tenderness

Meat tenderness is an important quality attribute and many studies have been conducted to reveal the underlying mechanisms behind meat tenderization. The degradation of muscular proteins by endogenous proteases in postmortem muscle has been recognized as a major contributor to the development of meat tenderness. This proteolytic process is affected by the changes in intracellular conditions of muscle during postmortem storage, including the pH decline, the increase in ionic strength, the decrease in reducing power, and the accumulation of reactive oxygen and nitrogen species. Accordingly, those biochemical events occurring in postmortem muscle can interplay with proteolysis and contribute to the variation of meat tenderization. Through proteomics, differential protein expressions and modifications have been identified and their associated pathways can provide the molecular basis for explaining the variability in meat tenderness. Proteins that are identified as potential biomarkers for predicting the changes of meat tenderness can be categorized into seven categories, including metabolic enzymes, stress-related proteins, heat shock proteins, calcium channel components, myofibrillar proteins, proteases, and apoptotic proteins. This article briefly summarizes the main biochemical pathways involving candidate protein biomarkers to enable a better understanding of the development of meat tenderization.