Tag: dielectric heating

Dielectric heating is also called microwave heating or high frequency heating. Dielectric energy is form of electromagnetic energy. They are transmitted as wave which penetrate food and are then absorbed and converted into heat.
Principle: the majority of food contain substantial proportion of water. The molecular structure of water consist of negatively charged oxygen atom separated from positively charged hydrogen atom and this form an electric dipole. When a microwave or radio frequency electric field is applied to a food, dipoles in water and in some ionic components such as salt attempt to orient themselves to the field (in a similar way to a compass in a magnetic field). Since the rapidly oscillating electric field changes from positive to negative and back again several million times per second, the dipoles attempt to follow and these rapid reversals create frictional heat. The increase in temperature of water molecules heats surrounding component of food by conduction and or convection. The depth of penetration of microwaves energy is determined by
1. Dielectric constant
2. Loss factor of food Read more