A System for Food Drying Using Humidity Control and Low Temperature

P. Catalano, F. Fucci, F. Giametta, G. La Fianza


Drying and maturation processes are widely used in food production, but a scientific approach
has not so widely been applied, so rather empiric rules are often used to set up industrial
production, particularly in small-medium firms. Humidity control of food is often achieved by
regulation of the R.H. (Relative Humidity) and room temperature, taking into account the water
evaporation inside the food matrix according to the air velocity. For each phenomenon a
mechanism is ,in general, expressed using a driving force and a transport coefficient. In our
model only the dominant mechanisms are considered. For the moisture diffusion in the solid
toward its external surface we applied a concentrated parameter model, constant properties and
no shrinkage. The system proposed in this paper consists of humidity and temperature control
during the food drying process by using a particular dehumidifier equipped with a desiccant rotor
containing silica gel. In each experiment we controlled the air humidity, temperature and velocity
and we monitored the moisture content and temperature as function of time. Most of researchers

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