ABSTRACT
Drying characteristics of Mulberry (M. alba) including sorption isotherms and
drying kinetics were investigated. Adsorption and desorption isotherms at 10, 20
and 30°C and isostetic heats of sorption were determined. At higher water
activities, as the temperature was increased, a crossing of the isotherm curves
was detected. Some hysteresis effect decreasing with higher temperature was
observed. Mulberry was dried in a pilot plant tray drier with a constant air
velocity of 1.2 m SK’ at 60, 70 and 80°C. Only falling rate drying periods (three
falling rate periods) were observed in the mulberry drying experiments. The
dijfusivity values changed from 2.32 x lo-” to 2.76 x lop9 m2 s-t within the
given temperature range. Efiect of temperature on the diffusivity was expressed
by an Arrhenius relation with an activation energy value of 21.2 Wmol-‘.
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