Blanching at 180 ◦C, 210 ◦C and 240 ◦C for 15, 10 and 8 min,
respectively yielded the desired result. Intermittent heating
and blowing of air largely helped in maintaining the surface
temperature (99 ◦C max) of the slices. Slight browning of the
sample surface was noticed when the zone temperature was
high (240 ◦C), while blanching at 180 ◦C required longer duration
(15 min), as compared to 210 ◦C. Hence, blanching at 210 ◦C
was selected for comparative studies as well as for drying
experiments.