Effective thermal diffusivity of perishable produce as a function of temperature by transient method

Abstract

Effective thermal diffusivity of vegetables/fruits has been determined in the temperature range 0 – 45ºC. The thermal diffusivity is measured by a transient technique using temperature probes (thermocouples) inserted in the sample at a distance of 2 mm. One dimensional transient temperature distributions T(r, t) generated in the sample are measured at different positions at discrete times. An ADAM data acquisition module is used to simultaneously read and store the temperature after every one second interval with a precision of 0.001ºC by GeniDaq software. The cubic spline interpolation technique is used to calculate effective thermal diffusivity. The temperature dependent thermal diffusivity has been determined for Cucumis sativus (L), Luffa acutangula (L.), Lagenaria siceraria (L.), Malus domestica (L.) and Musa acuminate (L.). The effective thermal diffusivity increases continuously with temperature.