Seeing a rainbow sparkle on slices of meat can make anyone pause and wonder if the meat is still good. The good news is the colorful sheen is just a natural science effect and not a sign of anything wrong.
Meat’s muscle fibers are layered, and when light hits thin slices, it refracts and scatters through these layers, creating a rainbow-like appearance similar to what you see in a prism. Moisture on the meat’s surface helps this effect by reflecting light more strongly.
This phenomenon is more visible when meat is cut across the grain and appears most frequently in beef but also happens with pork, bacon, ham, and even fish. Experts and the USDA reassure shoppers that the rainbow colors are perfectly normal.
To know if meat is safe, rely on your senses. Fresh meat smells mild or neutral; any strong or sour smell is a warning. The texture should feel firm, not mushy or sticky. Avoid any gray or green areas, which may signal spoilage.
When picking meat in stores, look for vibrant, fresh colors and intact, leak-proof packaging with no trapped air in vacuum-sealed products.
So next time you spot that rainbow on meat, remember it’s just a beautiful optical illusion caused by light, not a sign to toss your food.
