The effect of modified atmosphere packaging (70% O(2)/30% CO(2)) and skin packaging (no oxygen) on protein oxidation and texture of longissimus dorsi was investigated during storage for 14 days at 4°C. High oxygen atmosphere resulted in reduced tenderness and juiciness and SDS-PAGE revealed cross-linking of myosin heavy chain through disulfide bonding, and the content of protein thiols was reduced indicating protein oxidation. Myofibril fragmentation was reduced in meat stored in high oxygen atmosphere indicating less proteolysis and/or cross-linking of proteins. Protein carbonyl content was not affected by the packaging atmospheres. This study shows that packaging in modified atmosphere containing a high level of oxygen can result in protein cross-linking and reduced tenderness and juiciness of the meat.