A simple method to estimate the thermal diffusivity of foods

This work shows an alternative method to determine the thermal diffusivity of wheat flour and cassava, by means of experiments. It was considered as a model for analysis a semi-infinite solid, represented by an aluminum container filled with flour, an incandescent lamp as a heat source and thermocouple sensors for acquisition of electronic temperature signal. From the moment in which the temperature on the upper surface of flour remained constant, the data were acquired at a predefined time interval, which allowed obtaining the thermal diffusivity. To evaluate the results achieved from the experiments, it was carried out a simulation in Partial Differential Equation Toolbox of Matlab R2015a, in order to compare the temperature distributions within the solid. It was verified that the values showed by simulation are satisfactorily close to the experimental values.

Practical applications

Some information about physical properties of foods usually are not available, therefore, a simple method to estimate the thermal diffusivity could be useful, once it influences the quality control of foods. Thus, the findings of this study may facilitate the food industry, assisting the design, and simulation of process, such as heating, cooling, freezing, defrosting, frying, and storage.