Abstract
The applications of microwaves for household use and processing at the industrial level have gained immense importance over traditional conduction or convection heating systems. Microwaves can heat and toast raw kernels such as peanuts, maize, hazelnuts, sunflower seeds, cocoa beans, coffee, and other food kernels with a notable decrease in energy consumption and heating time because this technology generates volumetric heating in each kernel with the absorption of the incident energy. However, for raw kernels packaged for toasting, the availability of a continuous or at least intermittent movement device is highly required in microwave ovens. This chapter will briefly discuss the basic principles available in microwave ovens based on the dielectric heating modes. Recent advances and challenges in uniform heating using movement or rotating devices. Also, the pros and cons of applying microwave energy in toasting processing operations will be discussed.