Development and characterization of extruded biodegradable foams based on zein and pearl millet flour

Paper in proceeding, 2011

The aim was to establish a preliminary processing window for extrusion foaming of blends of zein and pearl millet flour and to estimate the properties of the extrudates. The weight ratios of zein:pearl millet flour were 75:25, 72:28 or 70:30 and foamed extrudates with a circular geometry were produced with bulk densities between about 350 and slightly higher than 500 kg/m 3 . Compounds with a higher zein content tended to give a more foamed structure. The stiffness (modulus) in compression of the foams was in the range 25-50 MPa with higher values at a higher bulk density. At a given density, the specimens with a higher zein content appeared to give a stiffer structure.