Estimation of thermal diffusivity of foods using transfer functions

The effective thermal diffusivity of foodstuffs was estimated from time–temperature histories in the geometric center of samples exposed to heating and cooling processes.Transfer functions methodology was used as an alternative method to estimate the thermal diffusivity assuming that conduction was the main heat transfer mechanism. The samples were characterized as delayed first-order systems with unit gain, dead time (L  ) and time constant (ττ).The results were compared with those obtained from the fhfh value and with results reported in the literature.