Research Progress of Radio Frequency and Microwave Technology in Food and Agricultural Products Sterilization

Radio frequency (RF) is an efficient, uniformity heating method, which can be used for pasteurization and disinfestations. It also shows the superiorities on low-moisture content food heating comparing with microwave (MW) heating. This manuscript describes the mechanism, effect and modeling of RF pasteurization/disinfestations. When low frequency electromagnetic wave is used for heating treatment, the contribution of dipole relaxation to temperature rise decreases, while the proportion of ion conduction increases, and low moisture content food has low thermal conductivity. These factors makes RF heating suitable for sterilization and insecticidal operation of low moisture content food such as grain. In addition, RF frequency electromagnetic wave length makes the heating has better penetration and internal heating uniformity. And the RF system can easily integrate hot air, vacuum, thermal circulation and other heating methods, so as to improve the heating efficiency, enhance the purpose of product quality. In conclusion, RF has great advantages in heating efficiency compared with traditional heating method, which can significantly reduce the loss caused by harmful organisms in grain with low water content, which is of great significance to the preservation of agricultural products. This paper provides the basis and reference for the application of RF technology in the preservation of grain with low water content.