You might have noticed a strange rainbow-like shine on slices of meat and wondered if it’s safe to eat. Many people have the same question, but the answer is simple: it’s a natural optical effect, not a sign of spoilage.
This colorful shine happens when light hits the layers of muscle fibers, fat, and iron in the meat. Thin slices cut against the grain show this effect best because the light bends and separates into colors, like a tiny rainbow. Moisture on the meat’s surface makes the colors even more visible.
While beef is the most common meat to show this, pork, bacon, ham, and fish can also have this rainbow shimmer. The USDA says this is normal and harmless.
Still, always check for freshness by smelling the meat and feeling its texture. If it smells sour or feels sticky, don’t eat it. Watch out for unusual colors like gray or green patches.
When buying meat, choose cuts that look bright and fresh. Make sure packaging is sealed and intact.
In the end, the rainbow effect on meat is just light playing tricks. If your meat passes the freshness test, it’s perfectly fine to cook and enjoy.
