Electromagnetic fields

Regions of force surrounding moving electric charge, carrying both electric and magnetic components and a definite amount of electromagnetic energy. In the food industry they are put to work in dielectric heating, where microwave or radio-frequency fields agitate polar molecules in the food and heat it rapidly from within. Microwave fields at 2450 MHz and radio-frequency fields at 13.56 or 27.12 MHz heat foods volumetrically by rotating polar molecules — mainly water — thousands of millions of times per second. Uniformity depends on field distribution and product geometry, so applicator design and turntables matter as much as power.