Corn smut

Cuitlacoche (also huitlacoche ) is a specialty of Mexican cuisine, from the fungus Ustilago maydis ( disease: corn smut ) is infested corn kernels. The grains swell by the parasite infestation and turn black. The Aztecs allegedly scratched a corn kernels, so that they were more easily infected.

In China, a related fungus is eaten, the rice grains attacks, and the practices prevalent in parts of East Asia Angkak or Japanese Koji (red rice).