The optimum extraction condition was
determined by superimposing the contour plots of
the significant responses. The final product would
be considered optimum with high yield and less
time of processing. Emphasis was placed on RSS
and clarity since they were important indexes of
physical characteristics of all responses. RSS could
be represented better than yield and the clarity and
browning index were in the same trend. The
criteria produced an optimum region in the
superimposed plot if RSS was