Vitamin E supplementation and improved oxymyoglobin stability

The bright red color of beef is due to oxymyoglobin. This ferrous heme protein is readily oxidized to brownish-red metmyoglobin during retail 

The mechanism by which vitamin E improves myoglobin stability is not understood. Vitamin E is lipid-soluble and resides in the membrane portion of skeletal muscle myofibers, while myoglobin is water-soluble and found in the sarcoplasm. The degradation of lipids generally results in 

It is important to note that in these studies of vitamin E supplementation, it is the stability of oxymyoglobin that is improved. There does not appear to be any effect of vitamin E supplementation on the absolute concentration of myoglobin. In addition, consumers often associate discolored meat with a high microbial load. While meat color is not necessarily an adequate indicator of bacteriological quality (Faustman et al., 1990), Arnold et al. (1992a) have shown that bacterial growth on meat from vitamin E supplemented cattle is similar to that of meat from control animals. Thus, while the color stability of vitamin E supplemented beef may be improved, microbial growth is unaffected. The question of whether such enhanced color stability masks a natural deteriorative process must be addressed and requires further research. 

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