The frequency of 300 MHz microwave electromagnetic waves. The material is heated in the water medium is a polar molecule. It is in a rapidly changing high-frequency electromagnetic field, its very sexual orientation will change with changes in external electric field, causing friction between molecular motion and effects. At this point the microwave field in the field can be converted into medium heat, temperature of materials to produce a series of heating and expanding physical and chemical processes to achieve the purpose of microwave heating and drying. 

 Mechanism of microwave sterilization 

 Microwave sterilization is the use of the thermal effects of electromagnetic fields and biological effects of interaction results. Microwave heating effect on the bacteria is to protein denaturation, loss of nutrition of bacteria, the conditions of reproduction and survival and death. Biological effects of microwave on bacteria microwave electric field can change the permeability of the membrane section, bacteria thus malnutrition, not the normal metabolism, bacterial structure and function disorders, growth was inhibited and death. In addition, the determinant of genetic stability of normal growth and reproduction of nucleic acid (RNA) and deoxyribonucleic acid (DNA), relaxation by a number of hydrogen bonds, breaking and reorganization, and induce genetic mutations, or chromosomal aberrations whispering sound, or even broken.