On-off temperature and power controller for improvement of the processes conditions assisted with microwaves

Abstract

Introduction: The use of microwaves in the process of fruits and vegetables dehydration is presented as an alternative process to the conventional ones because of the benefits in a reduction of transport costs, less processing time and final product volume, as well as a greater time of conservation and storage. Objective: Therefore, the aim of this study is to modify the microwave radiation supply, implementing an ON-OFF control of power and temperature in order to evaluate these parameters in the process and energy yield in the papaya. Methodology: For the development of the project, a factorial design of experiments was done taking into account the time on and off of the radiation and the sample geometry (slice and cube); runs were performed in duplicate and randomly in the modified microwave oven of 2.45GHz and 1kW of power. Results: The amount of moisture removed, the energy yield of the process and the initial organoleptic properties were analyzed. In the tests carried out, a maximum energy yield was 0.014kg/kJ with a reduction of 86% of the papaya sample weight processed in the radiation rate of 6x12 for a slice of 0,01m of thickness. Conclusions: It was achieved modification of the control in the microwave oven and the runs were carried out concluding that the parameters evaluated and are influential in the process and can be achieved moisture removal of 86%.

Keywords

• Controller
• Microwave
• Power
• Timing
• Temperature