Dielectric (microwave (MW) & radio frequency (RF) energy Infrared (IR or radiant) energy forms of electromagnetic energy transmitted as waves, penetrate food, be absorbed & converted to heat. Ohmic (or resistance) heating uses electrical resistance of foods to directly convert electricity to heat. Dielectric & ohmic heating are direct methods; heat is generated within product IR heating is an indirect method relies on heat generated externally; applied to the surface of food mostly by radiation, by convection & to a lesser extent, conduction.

2. • It is the transfer of energy through matter from particle
to particle. It is the transfer and distribution of heat
energy from atom to atom within a substance.
• When heating a pan of water on the stovetop, the heat
from the pan is transferred to the water via conduction.
• When an egg is placed in the hot water, heat is
transferred from the hot water to the egg via
conduction.
• Conduction also occurs as the heat from the egg white
in turn cooks the yolk at the center of the egg.

3. • It is the transfer of heat and other
atmospheric properties by the movement
of masses of air, particularly in an upward
direction.
• Boiling water - The heat passes from the
burner into the pot, heating the water at
the bottom. Then, this hot water rises and
cooler water moves down to replace it,
causing a circular motion.

4. • Radiation: Radiation: energy that is radiated or
transmitted in the form of rays or waves or
particles and
It is the heat transfer by electromagnetic waves
or photons. It does not need a propagating
medium. The energy transferred by radiation
moves at the speed of light. The heat radiated
by the Sun can be exchanged between the
solar surface and the Earth's surface without
heating the transitional space.

16. MW: Dipole Rotation RF: Ionic Translation
(polarisation)