The thermal and physical properties of cucumbers
and the convective heat transfer coecient (h) must be
known before modeling heat transfer rates during the
blanching of cucumbers. The density of 20 cucumbers
was calculated from the ratio of mass of cucumbers to
the volume. Cucumber volume was obtained by the ¯uid
(ethanol) displacement method (Mohsenin, 1986).
Speci®c heat was measured by means of a Perkin±
Elmer DSC 7 dierential scanning calorimeter equipped
with intracooler II refrigeration unit and dry box (Perkin
±Elmer, Norwalk, CT). The DSC was calibrated with
indium (temperature and enthalpy) and dodecane
(temperature) before use. Samples were weighed (30 mg)
in the manufacturerÕs stainless steel pans and run from
20°C to 95°C at a heating rate of 3°C/min using an
empty pan as the reference. Speci®c heat was calculated
by the software provided by the DSC manufacturer. To
ascertain the accuracy of the measurements, the speci®c
heat of HPLC-grade water was measured and found to
be within 2% of published values. The speci®c heat of the
mesocarp, endocarp and whole cucumbers was determined.
Duplicate samples for speci®c heat measurements
were obtained by grinding whole, mesocarp or endocarp
sections of 20 (10 for each duplicate) cucumbers.