These are grains of wheat from a tomb.
It is from a grave at Thebes. Wheat and barley (Hordeum vulgare) were the basic foodstuffs of ancient Egypt. The wheat was an old form, known as emmer, Triticum dicoccum. The harvested grain was stored in a granary. A daily job was grinding the grain into flour to make bread. Bread was the staple food in ancient Egypt, eaten every day and at most meals. These are grains of wheat from a tomb. It is a natural product. The age of this wheat is not known.