The functional properties of popped, flaked, extruded and roller-dried foxtail millet (Setaria italica)

Foxtail millet grains were decorticated in rice-milling machinery and the decorticated millet was processed to prepare flaked, extrusion cooked and roller-dried products, whereas the native grains were subjected to high-temperature, short-time treatment to prepare popped millet. The nutrient composition and some of the functional properties of the products were determined, principally solubility and swelling power in water, oil absorption capacity and pasting characteristics. Carbohydrate and lipid profiles of the products were also studied. The changes in the starch granular structure caused by heat treatment were examined by scanning electron microscopy. The degree of starch gelatinization was highest in the case of roller-dried millet followed by popped, flaked and extruded products. It was concluded that the cereal processing technologies that were investigated could be successfully applied to foxtail millet to prepare ready-to-eat or use products, thereby increasing its utilization as a food.