Maize industry. Grains of maize (Zea mays) on a factory conveyor belt. Maize is one of the world's most important crops. It can be eaten as corn-on- the- cob, as popcorn, or ground into corn flour. It can be distilled to make a whisky, and extracts are used in cooking oil and margarine. Maize is a good source of potassium and vitamin A, and is high in fibre. Photographed in Argentina.