Shrinkage of carrots during drying in an inert medium fluidized bed

Agricultural food products and specially root vegetables undergo several physical and structural modifications during the drying process. Shrinkage of root vegetables during drying is important not only from the viewpoint of material end-use but also for simulation problems. In this paper the shrinkage of root vegetables is studied in a pilot-scale, inert medium fluidized bed dryer. Cylindrical carrot samples were utilized as the test media, providing simulants for high moisture content food systems. The effects of various parameters such as air temperature, air humidity, sample diameter, sample initial moisture content, existence of inert particles and air velocity were investigated. It was found that the shrinkage of root vegetables during drying in a fluidized bed could be well correlated with moisture content of the sample during drying. Air velocity, temperature and presence of inerts did not show significant effects on shrinkage in this system. (C) 2002 Elsevier Science Ltd. All rights reserved.