It has long been known Prime-grade beef is often more tender than Select-grade beef. The biological factors explaining for the tenderness differences, however, have not been well-defined. This project was conducted to evaluate a new hypothesis that may explain the tenderness difference between high- and low-marbled steaks.
Finishing diets typically contain lipids which could increase overall oxidative reactions stress in live cattle. For cattle with more marbling, there may be an inherent increase in oxidative properties caused by production of reactive oxygen species (ROS). Research has shown animals generate ROS in response to oxidative stress. The most predominant ROS are superoxide, peroxide and hydroxyl radicals. These compounds have a chemical structure consisting of a single “unpaired” electron, making them highly reactive in the body. As such, their presence could disrupt typical postmortem changes in muscle, possibly promoting further protein degradation and enhancing tenderness. The mechanism of these changes remains to be uncovered.