Why Some Beef Stays Red Longer
Comparison of Gas Treatments of High Oxygen, Carbon Monoxide, and Nitric Oxide on Ground Beef Color in Modified Atmosphere Packaging
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Scientists tested three ways to pack ground beef to keep it looking red. One way used carbon monoxide — it stayed bright red the longest. Another used nitric oxide — it started dark but got redder over time, and inside, it stayed pink even when cooked. It also kept the meat from going bad as fast as air-packed beef.
Surprising Findings
Nitric oxide packaging produces a more stable internal cooked color than carbon monoxide, even though CO wins for surface redness.
Everyone assumed CO was the best at locking in redness everywhere—but NO beats it inside the meat after cooking, which no one expected.
Practical Takeaways
If you buy ground beef that looks unusually pink inside after cooking, check the package label—look for 'nitric oxide' or 'NO-MAP'—it’s safe, just misleading.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Scientists tested three ways to pack ground beef to keep it looking red. One way used carbon monoxide — it stayed bright red the longest. Another used nitric oxide — it started dark but got redder over time, and inside, it stayed pink even when cooked. It also kept the meat from going bad as fast as air-packed beef.
Surprising Findings
Nitric oxide packaging produces a more stable internal cooked color than carbon monoxide, even though CO wins for surface redness.
Everyone assumed CO was the best at locking in redness everywhere—but NO beats it inside the meat after cooking, which no one expected.
Practical Takeaways
If you buy ground beef that looks unusually pink inside after cooking, check the package label—look for 'nitric oxide' or 'NO-MAP'—it’s safe, just misleading.
Publication
Journal
Foods
Year
2024
Authors
Benjamin J. Carpenter, Thomas W Dobbins, M. S. Hernandez, Samantha N. Barker, Kaitlyn R Loomas, Wesley N. Osburn, J. Legako
Related Content
Claims (6)
When beef is packed with a gas called nitric oxide, it stays pink inside even after being cooked all the way through—unlike beef packed with other gases—because the nitric oxide binds to the meat’s natural pigment and locks in the pink color.
When you package ground beef with nitric oxide gas, it leaves behind more nitrite and nitrate chemicals than other gases like carbon monoxide or plain oxygen—and when you cook the meat, even more of these chemicals show up, maybe because the gas breaks apart inside the meat.
When meat is exposed to carbon monoxide, it turns and stays red—even if it's going bad—so it looks fresh longer, even though bacteria might already be growing inside.
When you package ground beef with nitric oxide gas, it looks kind of dull at first, but over five days in the store, it turns a bright, fresh-looking red and stays that way—just like beef packed with carbon monoxide—because the gas slowly turns the meat’s natural pigment into a stable red color.
Putting a tiny bit of carbon monoxide in the plastic wrap around ground beef keeps it looking bright red for longer—up to five days—better than other gas mixes, because it locks the meat’s natural red color in place.