2.3.3. Analyses of the extruded products
2.3.3.1. Expansion ratio
The diameter of 20 pieces of extruded products was measured using a caliper (Mitutoyo, Tokyo, Japan) and the expansion ratio was calculated by dividing the average diameter of the products by the diameter of the die.
2.3.3.2. Bulk density
Bulk density (BD) (g/cm3) of 10 pieces of extrudates was calculated according to Eq. (2) (Bulk density (g/cm3) Alvarez-Martinez, Kondury, & Karper, 1988), where m is mass (g) of a length L (cm) of extrudate, with diameter d (cm).