Innovative applications, limitations and prospects of energy-carrying infrared radiation, microwave and radio frequency in agricultural products processing

As electromagnetic waves of particular bands, energy-carrying infrared radiation, microwave, and radio frequency transfer heat, which affects biological functions and promotes moisture separation in agricultural product processing. Such processing has been successfully applied in drying, enzyme inactivation, dry-blanching, post-harvest pest control, thawing, and other processes. There are broad application prospects for energy-carrying electromagnetic waves because of their advantages of clean and efficient energy that is precise and easy to control in agricultural product processing. Herein, we reviewed the development, application prospects, and limitations of energy-carrying infrared radiation and microwave, as well as radio frequency, in agricultural product processing. The advantages of combining microwave and infrared energies for drying were studied. Combining these energies with the application of intelligent processing technology, sensor technology, artificial neural networks, and computer vision is discussed. The limitations of infrared energy are waste heat dissipation and insufficient penetration, and microwave energy absorption is affected by many factors such as dielectric properties and material layer thickness. Microwave-infrared vibrating bed drying (MIVBD) can significantly increase the drying uniformity and drying efficiency, and decrease any ‘hot spot’ and ‘cold spot’ problems that normally occur in electromagnetic wave drying. This intelligent technology includes sensor technology, artificial neural networks, and computer vision, which is applied to electromagnetic wave processing such that the entire process can be monitored in real-time online, and thus, product quality can be ensured.