Drying kinetics of rose hip fruits (Rosa eglanteria L.)

Simulation of dehydration in beds for food particles demand long computing times. So, models for equipment design should be as simple as possible. An equipment with particulate material can be visualised as formed by a number of beds of given depth, in turn composed of thin layers. Therefore, thin layer dehydration studies become essential as a step for developing updated methods for equipment design. Such studies are especially needed in products such as rose hips for which scarce if any drying kinetic data is available. Drying curves were experimentally determined for rose hip fruits, using air at: 50, 60, 70, 80 °C; relative humidities: 5%, 50% and velocities: 1, 2, 3, 5 m/s. A short time predictive model for diffusion inside solids was selected to interpret the data with satisfactory accuracy. By this fitting procedure, diffusion coefficients of water in rose hips were determined to vary between 7.501 × 10−11 (50 °C) and 3.367 × 10−10 (80 °C) m2/s, with an Ea = 46 kJ/mol.