**4. Conclusions**

The viscoelastic parameters (Gʹ, Gʹʹ, and Tan δ) were affected by xanthan gum concentration, inducing a weakening of the existing structure of masas from extruded nixtamalized corn flour. Tortillas from masas with high values of Tan δ improved their textural characteristics. The optimal combination of variables to obtain ENCF using a single-screw extruder was: T=116.67°C/MC= 29.13% / XG= 0.65%. The optimal conditions were validated experimentally, and results were similar to those values predicted by RSM. Besides the information of basic nature that can be obtained with the dynamic method, it can be considered a practical rhelogical tool capable of differentiating masa from extruded nixtamalized corn flours.
