EFFECT OF TEMPERATURE ON THE PHYSICAL CHANGES AND DRYING

In this study, drying kinetics of autochthonous variety Požegača plum was exa-mined in a laboratory dryer at three temperatures. The whole plum fruits, to-gether with the kernels were subjected to the drying process. The effect of dry-ing has been examined at temperatures of 55, 60 and 75 °C, with a constant air velocity of 1.1 m s-1. The corresponding experimental results were tested using six nonlinear regression models. Coefficient of determination (R2), stan-dard regression error (SSE), model correlation coeficient (Vy), as well as the maximum absolute error (ΔY) showed that the logaritmic model was in good agreement with the experimental data obtained. During drying of plums, the effective diffusivity was found to be between 5.6×10-9 for 55 °C and 8.9×10-9 m2 s-1 at 75 °C, respectively. The physical characteristics of fresh (length 39.64 mm and width 29.15 mm) and dried (length 37.52 mm and width 22.85 mm) plum fruit were determined. Finally, by chemical analysis, the contents of mic-ro-and macro-elements (Fe, Mn, Cu, B and N, F, K, Ca, Mg and S) in the skin and flesh of the dried product, prunes, has been established