Modified-atmosphere packaging containing 80% oxygen and 20% carbon dioxide (HiOx-MAP) is widely used in fresh beef at retail to delay discoloration and hold cherry-red color of beef for a longer time. However, previous studies have shown that HiOx-MAP considerably decreases tenderness of beef steaks during retail display. The decrease in tenderness is due to protein oxidation, which likely leads to protein polymerization (aggregation).
There is more to discover about protein oxidation, especially its mechanism and control measures.