These
results suggest that soy protein can modulate shortness of texture
in gelled confections without sacrificing the structural integrity of
the system at concentrations below 50% soy-for-starch displacement.
A similar progressive decrease in hardness was observed by
Limroongreungrat and Huang (2007) in pasta upon addition of
soy protein. The decrease in hardness could have resulted from
direct disruption of the starch network or, as has been shown in
bread systems, the hydrated soy protein may have acted as a macromolecular
plasticizer and thereby lowering starch-network stiffness
(Vittadini and Vodovotz 2003). It is important to note that hardness
in gelled confections can be misrepresented by surface drying,
a phenomenon caused by moisture loss that manifests as a “skin”
(Ziegler and others 2003), that is not necessarily representative of
the total physical nature of the sample. However, surface drying
only became more noticeable at high SPI concentrations yet did
not mask the overall softening effect.