The main objective of solar drying in horticultural products is to reduce the moisture content to a required level that allows a safe and extended shelf-life duration. Solar drying is also considered as a significant technique for food security and quality. Drying of plums were carried out in a drying chamber attached with a flat plat solar collector at three different temperatures and three air velocities. The whole plum fruits, were subjected to the drying process. The research was carried out in completely randomized design (CRD) with temperature and air velocity as factors having three levels with three replications. During drying of plums, the maximum moisture loss (wet basis) recorded 2.629 % at 65 oC while minimum recorded 2.459 % at 45 oC, and 2.550 % at 0.5 m. s-1 air velocity followed by 2.549 % at 1.0 m. s-1. Highest activation energy of 46.97 kJ.mol-1 recorded at 65 oC while minimum of 38.19 kJ.mol-1 recorded at 45 oC. Similarly, maximum activation energy of 45.07 kJ.mol-1 recorded at 0.1 m. s-1air velocity followed by 43.95 kJmol-1 at 0.5 m. s-1. The maximum moisture diffusivity of 1.76x10-9 recorded at 65 oC while minimum of 0.91x10-9 recorded at 45 oC. In all the six best published models for plums, the modified page model gave significant results with R2 of 0.99, RMSE value of 0.08, and a X2 value of 0.62. Temperature showed significant effect on increase of moisture loss hour-1, activation energy and moisture diffusivity. Air velocity showed non-significant results on moisture loss.
Key words: Airflow, Heat transfer, Forced-air drying, Plum, Thin layer approaches