Extrusion of starch and water at temperatures above 100 C leads to the formation of voids, due to the expansion of steam as the extrudate exits at the high-pressure conditions of the die [4]. It can be divided into three mechanistic steps: nucleation, bubble growth and bubble stabilization. Typical structure of the extruded starch foam is presented in Fig. 2a. The foam cellular structure can be significantly affected by extrusion conditions (i.e., barrel tem-perature, die diameter, and screw speed), and material composi-tions, (i.e., starch type, feed moisture, and nucleation agent concentration), as reported in several works