Three factors three level Box-Behnken response surface experimental
design (BBD) and response surface methodology were
employed in this study to optimize the process variables for
MIE process for extraction of betalain from dragon fruit peel.
Second order polynomial mathematical model was developed
with good coefficient of determination values (R2 > 0.95)
and analysis of variance showed the significant effect of each
process variables on extraction of betalain. Optimum conditions
for this MIE process were found to be temperature of
35 C, mass of the sample of 20 g, and treatment time of
8 min. Under these conditions, 9 mg/L of betalain content
was extracted (Willet, 2002). The antioxidant activity of
extract was evaluated by applying the DPPH method. This
result indicates the effectiveness of MIE process as a powerful
extraction technique with shorter extraction time.