Brown Colour of Meat

The brown colour of meat is due to:

Correct Answer: Metmyoglobin

The brown colour of old/stale meat is due to Metmyoglobin (MMb), formed when myoglobin is oxidized (Fe²⁺ → Fe³⁺).

Myoglobin Pigment Summary

• Myoglobin → Purplish-red (deoxygenated state)
• Oxymyoglobin → Bright red (oxygenated — fresh meat surface)
• Metmyoglobin → Brown (oxidized — stale or old meat)
• Nitroso-haemochromogen → Pink (cured and cooked meat)

Metmyoglobin formation is an indicator of meat deterioration. Reducing agents (like ascorbic acid/Vitamin C) can convert MMb back to Mb, temporarily restoring red colour.