3.3. Optimization of roasting conditions
The optimal roasting temperature and time were obtained by
superimposing the contour plots of the responses. Fig. 2 shows
a region of the optimal roasting conditions for preparing beverage
from maize kernels. The optimal area of superimposed contour
plots, determined using an extraction yield of more than 0.1 g/g,
a free sugar content of less than 20%, a level of phenolic compounds
of 15 mg/100 mL or less, a DPPH radical scavenging activity of less
than 70%, and a sensory score for overall preference was at least 5.
The results show that the optimal roasting temperature and time