The aims of this study were to measure the rate and extent of
solubilisation for a series of TPS:PVOH blends. The extent of solubilisation
data has shown that predominantly PVOH remained at
the end of the digestion and that starch is almost entirely degraded.
The PVOH content significantly impacted on the rate of
starch solubilisation. The calculated 1st order rate constant for starch solubilisation, k2, decreased with increasing amounts of
PVOH. It is possible that PVOH forms a continuous phase and
encapsulates the starch and that inter-chain mixing and partial
phase miscibility between starch and PVOH at the interface may
be contributing to the reduced rate of starch hydrolysis in blends
with more than 50% starch.