Combined Effect of Extrusion Cooking and Hydrocolloids on Senegalese Rolled Millet Flour (“Arraw”) from Pennisetum glaucum L. R. Br

Abstract

Senegalese rolled flour, known as “Arraw”, is popular but has a long cooking time of 37 minutes. This study aimed to significantly reduce the cooking time by combining extrusion technology with binding agents (Arabic gum and maltodextrin) in various formulations. These formulations included EMAG7 (93% extruded millet + 7% Arabic gum), EMAG9 (91% extruded millet + 9% Arabic gum), EMMD11 (89% extruded millet + 11% maltodextrin), EMMD13 (87% extruded millet + 13% maltodextrin), and TrM traditional “Arraw” (100% non-extruded millet, as a control). The results showed total granule yields of 56% for EMAG7, EMAG9, and EMMD13, and 63% for EMMD11, compared to 70% for TrM (100%). Water absorption indices ranged from 3.57 to 4.56 g/g for the new formulations, compared to 1.04 g/g for TrM (100% millet) and 6.63 g/g for extruded millet flour (EM). Meanwhile, water solubility indices ranged from 11.31% to 15.24% for the new formulations, compared to 5.17% for TrM (100% millet) and 12.75% for EM. Cooking times ranged from 6 to 12 minutes for the new formulations, compared to 23 to 33 minutes for TrM (100% millet). Arabic gum and maltodextrin were excellent binders for extruded flour rolling. Maltodextrin significantly improved the solubility of precooked millet granules. This research demonstrates the potential of cooking extrusion in reducing cooking time while increasing water absorption and solubility of precooked rolled millet flour with relatively low porridge viscosity.