The Effect of Microwave Assisted Vacuum Drying of Pineapple (Case Study: Microwave Power)

Abstract

In this research the drying process of pineapple using microwave assisted vacuum drying was investigated using experimental. The microwave assisted vacuum dryer was used to study the effects of different microwave power densities on the temperature distribution, moisture content and drying time of dried pineapple. The microwave assisted vacuum dryer was operated at microwave powers of 800 W and 1,600 W under absolute pressures of 30 kPa. The sample is Sriracha pineapple rings to the size of the pineapple slices-outside diameter 65 mm, inside diameter 25 mm and thickness 10 mm. The dryer has a capacity of 1 kg sliced pineapple fruits per batch. With drying air temperature in cavity set at 70°C, pineapple from an initial moisture content of 80% can be dried to a final moisture content of 20% wet basis. Experiments show that in the case of high power level (1,600 W) ensured the shortest drying time and causes greater damage to the structure of pineapple. The microwave assisted vacuum drying with operating mode at microwave powers of 800 W and absolute pressures of 30 kPa to the best overall quality of dried pineapple and thus was chosen as the most appropriate technique for pineapple drying.