3. DETERMINATION OF MOISTURE BY INFRARED EMITTER
Principle
The method is based on the drying of food sample under an infrared emitter and its mass
is recorded as a function of time. The water molecules in the food evaporate because they absorb
infrared energy, which causes them to become thermally excited. Moisture contents can be
determined rapidly using this equipment, e.g.10-25 minutes. When heating a sample, there are
two effects applied; radiation and convection. IR is mainly absorbed by water vapour particles
and uniformly penetrates all sample structure. IR drying methods are not officially recognized
for moisture content determinations because it is difficult to standardize the procedure. Even so,
it is widely used in industry because of its speed and ease of use.