Oxidative stress may affect meat quality by interfering with collagen turnover by muscle fibroblasts

Oxidative stress in farm animals is an environmental/dietary factor that may contribute to the inconsistency in meat tenderness. This cell culture study investigated the ability of reactive oxygen species (ROS) to influence the turnover of intramuscular collagen, in terms of the balance between its degradation by the enzyme matrix metalloproteinase-2 (MMP-2) and its synthesis by intramuscular fibroblasts derived from 2 bovine muscles (longissimus dorsi, LD, and semitendinosus, ST). The potential for vitamins E and C to ameliorate the effects of oxidative stress on these fibroblasts was also studied.The response to oxidative stress treatments and combinations of vitamins C and E differed widely between cells derived from each muscle. Generally, ROS increase MMP2 activity and reduce collagen synthesis. Vitamins generally tend to counteract the effects of ROS on collagen synthesis. Oxidative stress may decrease synthesis of new collagen by intramuscular fibroblasts in some muscles, which could lead to decreased collagen solubility and hence increased meat toughness.