Applications of Microwaves in Dairy Industries

The growing need for preservation of nutrients from degradation during pasteurization, sterilization, and other high temperature treatment of dairy and its products has demanded a less severe form of heating such as microwave (MW) to improve its shelf-life. The dielectric properties of the food material play an essential role in converting MW energy into heat energy. The right knowledge of food dielectric properties is necessary for heating required in the pasteurization process, designing heating equipment, and selecting optimal processing conditions (frequency, bed thickness, etc.) for uniform energy absorption. This chapter introduces the knowledge of how distribution and strength of electromagnetic fields in the food, its extent of absorption into the complex food system, propagation inside the system, and reflection from the food system play a major role during volumetric heating by MW. It also discusses the effect of MW on the intrinsic qualities of dairy, its advantages and disadvantages along with the recent exploration of MW heating.