Affiliation:
1. Institute of Mechanical Engineering, Warsaw University of Life Sciences—SGGW, 164 Nowoursynowska Street, 02-787 Warsaw, Poland
2. Department of Food Engineering, Faculty of Food Technology and Biotechnology, University of Zagreb, 6 Pierottijeva Street, 10000 Zagreb, Croatia
Abstract
Rehydration of food products was carried out in various amounts of liquid. The effects of the solid-to-liquid ratio on rehydration characteristics of dried red beets were investigated. Six values of the solid-to-liquid ratio (1:20, 1:15, 1:10, 1:5, 1:3, and 1:1) were taken into consideration. Red beets cubes (10 mm) were dried in a forced convection (2 m/s; 60 °C) and then rehydrated in distilled water at a temperature of 20 °C. The kinetics of mass gain, dry matter loss, water gain, moisture content increase, and volume increase were modeled using the empirical Peleg model which parameters have physical meanings. Equations were formulated to make the Peleg model parameters dependent on the solid-to-liquid ratio. The obtained results indicated that the amount of rehydrating water influenced the values of the model parameters and the course of dried red beets rehydration and helped explain the rehydration kinetics. The Peleg model can be recommended for describing the kinetics of mass gain (R2 = 0.9662–0.9895), dry matter loss (R2 = 0.7042–0.9881), water gain (R2 = 0.9732–0.9913), moisture content increase (R2 = 0.9770–0.9929), and volume increase (R2 = 0.9374–0.9847) during the rehydration of dried red beet cubes at all considered values of the solid-to-liquid ratio.