Mathematical Description of Changes of Dried Apple Characteristics during Their Rehydration

The mathematical description of changes dried apples characteristics (mass gain, volume increase, dry matter loss, rehydration indices, and colour) during their was performed. effect conditions both processes on model parameters were also considered. Apple slices (3 10 mm) cubes (10 in natural convection (drying air velocity 0.01 m/s), forced (0.5 2 fluidisation (6 m/s). Drying temperatures (Td) equal to 50, 60, 70 °C. process carried out distilled water at the (Tr) 20, 45, 70, 95 Mass loss modelled using following empirical models: Peleg, Pilosof–Boquet–Batholomai, Singh Kulshrestha, Lewis (Newton), Henderson–Pabis, Page, modified Page. Colour described through applying first-order model. Artificial neural networks (feedforward multilayer perceptron) applied make indices colour variations (ΔE) dependent characteristic dimension, Td, drying velocity, Tr. Page models can be considered most appropriate order characterise mass gain (RMSE = 0.0143–0.0619) increase 0.0142–0.1130), whereas Pilosof–Bouquet–Batholomai, Kulshrestha found 0.0116–0.0454). ANNs ΔE satisfactorily 0.0567–0.0802). Both influenced (although different degree) apple rehydration.