Understanding key component factors influencing the processing performance of extruded foxtail millet

This study elucidated the relationship among physicochemical properties of native/extruded foxtail millet, rheological properties, and processing performance of dough made from extruded millet through an in-depth exploration utilizing Pearson correlation, principal component, and K-means cluster analysis. Results showed that crude protein (8.21 %-9.27 %) and lipid content (1.47 %-5.19 %), peak time (4.6-5.3 min), and starch short-range order (R_995/1016) of native millet (1.564-1.901) were pivotal in shaping the molecular dynamics, degradation and reorganization processes during extrusion. Notably, heightened levels of crude protein and lipid content, alongside increased short-range order of starch in native millet, hindered the disorder and reorganization of starch, resulting in decreased expansion ratio, degree of gelatinization, water solubility index, and R_995/1016 value. These factors significantly impacted dough properties, leading to increased hardness and elasticity while concurrently reducing viscosity. K-means cluster analysis classified 11 foxtail millet varieties into three groups: those exhibiting high hardness (9.26 % protein, 3.77 % lipid and R_995/1016 = 1.87) (1), exceptional springiness (8.58 % protein, 1.77 % lipid and R_995/1016 = 1.75) (2), and advantageous viscosity (8.46 % protein, 1.82 % lipid and R_995/1016 = 1.71) (3).