Color enhanced SEM of sorghum flour particles, showing a relatively high incidence of starch grains (small globular particles, not shown in a color different from that used for the grain fragments). Image width: 1280 micrometers. Magnification: 78x if the image is printed 10 cm wide. Bar: 200 micrometers. Grain sorghum is the third most important cereal crop grown in the United States and the fifth most important cereal crop grown in the world. It is one of the most important staple foods for millions of poor rural people in the semiarid tropics of Asia and Africa. For some impoverished regions of the world, sorghum remains a principal source of energy, protein, vitamins and minerals. Sorghum grows in harsh environments where other crops do not grow well. It is used to make couscous, sorghum flour, porridge and other foods.