Expanded snack was prepared from partially defatted almond powder (PDAP) and corn flour (CF). Response surface methodology (RSM)was used to investigate the effects of extrusion conditions including feed moisture content (12–16%), screw rate (120–220 rpm) and different levels of PDAP (10–30%) on expansion ratio (ER), bulk density (BD), hardness, complexing index (CI), and scanning electron microscopy (SEM) properties of expanded product. Results showed that increasing PDAP content caused an increase in the hardness, BD and thickness of a cell wall and a decrease in air cell diameter and ER of the snacks. Moisture content was the most significant parameter in all extrudates, therefore increased feed moisture leads to a lower density, hardness, CI and higher expansion, whereas the increasing screw rate caused reduction of bulk density and hardness of the extrudate. Optimum condition was found to be the blends of PDAP:CF (21:79), screw rate of 219 rpm and feed moisture content of 16%.

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