FOOD TECHNOLOGY

Detailed explanation-1: -After exposure to the air for 15 minutes or so, the myoglobin receives oxygen and the meat turns bright, cherry red. After beef has been refrigerated for about five days, it may turn brown. This darkening is due to oxidation, the chemical changes in myoglobin due to the oxygen content.

Detailed explanation-2: -After a time, however, continued exposure to oxygen leads to the formation of metmyoglobin a pigment that turns beef brownish-red. The color change does not mean the meat is spoiled; it does suggest that the meat may not be as fresh.

Detailed explanation-3: -When exposed to air, myoglobin forms the pigment, oxymyoglobin, which gives meat a pleasingly cherry-red color. The use of a plastic wrap that allows oxygen to pass through it helps ensure that the cut meats will retain this bright red color.