Independent of storage temperatureWAI values of samples
stored for 24 h were not different (P = 0.05). When the
storage time increased WAI values decreased, a behavior
that agreed with the higher RS content since the crystallization
(i.e., retrogradation) that took place during storage
reduced the water absorption capability of starch. As mentioned
before, temperature did not show a significant effect
on WAI values (P = 0.0711) and storage time had a quadratic
effect on this parameter (P = 0.003). The following
equation described the mathematical model that described
this behavior as a function of the storage time (h)
(r2 = 0.90):
WAI ¼ 10:39 11:625 102h þ 18:316 103h2
The storage temperature affected WSI (P = 0.029) but storage
time did not show a significant effect (p = 0.7211). The
corresponding mathematical model is the following
(r2 = 0.72) where T is the storage temperature.
WSI ¼ 22:31 þ 6:78 102T þ 12:41 104T 2
The WSI values were higher than the WAI, pointing out
the higher amount of starch that was not transformed to
RS and was solubilized during the WSI determination.
These results agree with the RS contents since samples
showing the lowest RS levels also had the highest WSI
values.