EFFECT OF PRE-TREATMENTS ASSISTED MICROWAVE DRYING ON KINETICS AND ENERGY ASPECTS OF DRAGON FRUIT

Drying is one of the most effective preservation methods applied to increase the shelf life of agricultural products. In this study, the effect of different pre-treatments on drying dragon fruit with a microwave was investigated. It is also aimed to determine the drying method with the minimum energy consumption. Dragon fruit slices were dried by microwave at 300 W output power in four different pretreatments as ultrasound, gum arabic, sucrose, and without pretreatment. Pretreatment applications were carried out by performing ultrasound for 10 minutes on dragon fruit slices and soaking them in 10% gum arabic and sucrose solutions before drying. Results showed that the shortest and longest drying times were measured in gum arabic and without pretreatment, respectively. Time-dependent estimation data were calculated by six different thin-layer drying models, considering the drying times and moisture rates. Jena&Das model showed the best fitting performance. As a result, it has been determined that pretreatment applications reduce drying time and energy consumption. In addition, gum arabic pre-treatment is advantageous in terms of energy consumption in microwave drying of dragon fruit.