Why it Works: A Rainbow of Colors
Just as plants owe their green color to chlorophyll, meat is red because of a pigment called myoglobin. Myoglobin is a sensitive chemical, readily changing color when exposed to light or air. For example, without air (before slaughter or when packaged in the airtight packages often found at warehouse clubs) myoglobin colors meat a dark purple. When exposed to oxygen, myoglobin changes meat to its characteristic cherry red. Too much oxygen, combined with the florescent lights in the grocery store, can make the meat turn brown. Although this brown is unattractive, it doesn’t always mean the meat is spoiled—just handled improperly. The one color to watch out for is green; it signals bacteria growth and bad meat.