What component contributes to meat color and changes from red to brown to green when combined with oxygen?

Myoglobin is the correct choice because it is a protein found in muscle tissue that is responsible for the color of meat. Myoglobin contains heme, which can bind to oxygen and plays a crucial role in both the color and the nutritional value of meat.

When myoglobin is present in its deoxymyoglobin form (without oxygen), it appears red, which is typical for fresh meat. As myoglobin binds with oxygen, it forms oxymyoglobin, giving meat a bright red hue, often seen in freshly cut steaks in a display case. When exposed to air over time, myoglobin can oxidize and transition to metmyoglobin, causing the meat to take on a brownish hue.

In some circumstances, further oxidation of metmyoglobin can lead to the formation of various green pigments, although this typically occurs under certain conditions and isn't a natural part of the standard myoglobin color changes. This understanding highlights the importance of myoglobin in determining meat freshness and quality, as well as its visual cues for consumers.

Other choices, such as hemoglobin, while similar in function since it is also an oxygen-binding protein, is primarily found within red blood cells and does not contribute to meat color in the same way as myoglobin. Chlorophyll and