Power Modulated Microwave Processing

Microwave processing is recognized for its high heating efficiency, but its inherent nonuniform heating causes quality and safety issues in heated foods. Power modulation techniques are adopted to improve the heating uniformity, particularly for thawing. By lowering the power supply during heating, power modulation extends the heating time, enhancing heat transfer between hot and cold spots and mitigating the ‘thermal runaway’ effect. This chapter introduces microwave power modulation techniques, including cycled and inverter heating in magnetron-based microwave systems, and semiconductor-based solid-state microwave technology. The effectiveness of power modulation in improving heating uniformity and efficiency, as well as optimization strategies for better power modulation, are discussed.