EFFECT OF ETHANOL IMMERSION AND ULTRASOUND PRETREATMENTS ON THE KINETICS OF CONVECTIVE DRYING OF QUINCE

This work studied the impact of ethanol immersion (E), ultrasound (U), and ultrasound-ethanol immersion (UE) for 10, and 20 min on the drying characteristics of quince. After pretreatments, the samples were dried at a hot dryer at 90℃ and air velocity of 2 m/s. Drying time was reduced by 50% for samples pretreated in Ultrasonic-Ethanol (UE20) for 20 min. Moisture diffusion coefficient varied from 1.880 to 2.933×10-9 m2/s. The friction drag force, convective heat transfer coefficient, and convective mass transfer coefficient were 6.110×10-6 N, 24.077 W/m2K, and 0.020 m/s, respectively. The thermal conductivity, the specific heat, and the density of quince samples ranged from 0.5278 to 0.5876 W/m. K, 3554.00 to 3908.00 J/kg. K, and 814.95 to 904.60 kg/m3, respectively. Among all pretreatments, UE20 could prefer for significant decreases in the drying time and improve drying characteristics of quince at the industrial extent.