A grass species cultivated for its grain, which is used for food for humans, animal feed, and ethanol production. Sorghum originated in Africa, and is now cultivated widely in tropical and subtropical regions. Sorghum is the worlds fifth-most important cereal crop after rice, wheat, maize, and barley. Sorghum grain is gluten free, high in resistant starch, and more abundant and diverse phenolic compounds compared to other major cereal crop.