Microwave Heating Equipment for the Food Industry

Abstract

The application of microwaves becomes an emerging technology for some heating processes, such as tempering, cooking, blanching, pasteurization, sterilization, drying and baking. The equipment design is an utmost task including the right choice of food properties and the building materials as well as the microwave power, the use of on-off control and the position of the magnetrons. Besides, the number and position of the magnetrons will determine the uniformity of electromagnetic radiation distribution and the consequent temperature distribution. In this chapter, we will analyze different systems to heat foods in different states, i.e., liquids and solids. Continuous and discontinuous systems will be described, showing the equations that allow the simulation and the prediction of processing times. Besides, the mathematical simulation allows the calculation of mass and temperature profiles during the proposed processes. Several heating processes will be analyzed: cooking, pasteurization and drying. The advantages and disadvantages of the use of microwave in these processes will be discussed.