To obtain high mechanical properties, a homogeneous
dough was required. This was achieved by depolymerizing
PLA and acetylated starches. Ethanol
enhanced homogeneous dough formation except at
high PLA content of 25 and 70% amylose acetylated
starch–PLA foams. More mechanical energy was
required as ethanol content increased in acetylated
potato starch–PLA foam while the specific mechanical
energy requirement decreased as ethanol content
increased in 25 and 70% amylose acetylated
corn starch–PLA foams. PLA induced expansion of
all three acetylated starch–PLA foams. Because of
shear-induced depolymerization of PLA in 25 and
70% amylose acetylated starch–PLA foams, PLA content
affected bulk density, compressibility and specific
mechanical energy requirement differently by
type of acetylated starch. A higher degree of substitution
(harder agglomerate) of the acetylated starch
resulted in a higher radial expansion ratio, compressibility,
and specific mechanical energy requirement,
and lower bulk