<![CDATA[Sorghum flour has gained considerable attention as a gluten-free cereal with high nutritional value; however, its functional properties require improvement for industrial applications. This study aimed to investigate the effects of combined extrusion and enzymatic treatment on the morphological characteristics, thermal properties, and carbohydrate composition of pregelatinized sorghum flour. Three flour samples were prepared: native sorghum flour (PS1), extrusion-treated flour (PS2), and extrusion-enzymatic-treated flour with α-amylase (PS3). Morphological analysis was performed using polarized light microscopy and scanning electron microscopy. Thermal properties were assessed by differential scanning calorimetry (DSC), and carbohydrate composition was determined by high-performance liquid chromatography (HPLC). Results showed progressive loss of the Maltese cross pattern in PS2 and PS3, indicating disruption of crystalline structure, along with granule aggregation caused by amylose leaching. DSC analysis revealed that PS2 exhibited the most significant reduction in gelatinization temperature (To: 77.84 °C) and enthalpy (ΔH: 2.60 J/g) compared to native sorghum starch (To: 82.38 °C; ΔH: 7.52 J/g), representing a 57% decrease in ΔH. In contrast, PS3 showed no detectable endothermic peak (n.d.), indicating complete loss of residual crystalline structure. HPLC analysis confirmed extensive starch hydrolysis in PS3, with glucose concentration increasing more than 15-fold (77.31 mg/mL) compared to PS1, along with elevated maltose (12.05 mg/mL) and fructose (8.13 mg/mL) concentrations. These findings demonstrate that extrusion-enzymatic treatment effectively modifies sorghum flour structure, enhancing sugar release and altering thermal characteristics, thereby indicating improved functional properties for applications in instant foods, bakery products, and fermentation processes.]]>
