The measured values of freshly cooked brown rice were applied to
be the target values for calculating the desirability values of all
responses. It appeared that the optimal operating parameters
comprising WRR, MWL and HAT for individual response were not
identical; however, they fell within the range of experimental
conditions as shown in Table 3.
Generally, when the optimal process is needed, the responses
would not be separately deemed but the operating condition that
provides the maximum preference of responses in overall would be
chosen. If considering the optimal operating parameters for overall
responses, the maximum desirability index would be the criteria.
According to the calculation result of desirability value, the optimal
operating condition was 1.44 for WRR, 499.8 W for MWL and
89.99 C for HAT. At this condition, the desirability index is the
highest, 88%. It must be noted that the optimum WRR was in between
the selected range of study (1.3e1.7) whereas the optimum
values of MWL and HAT were close to the upper range (595 Wand
90 C, respectively). Therefore, it was expected that if the upper
limits of either MWL or HAT were raised, the desirability value
might be higher.