MC Determination Flashcards
It is the amount of water present in the grain, and is expressed in percentage (%).
Grain Moisture Content
Grain is ______, where moisture content may increase
or decrease depending on ambient temperature and
relative humidity.
Hygroscopic
When grain is exposed to air with low temperature
and high relative humidity (RH) the grains will absorb
water from the air.
Re-wetting
When grain is exposed to air with high temperature
and low RH the grains will release water to the air.
Drying
Recommended MC for Drying
< or equal to 14%
Recommended MC for Drying
< or equal to 14%
Recommended MC for milling
13-14%
Recommended MC for seed storage
< or equal to 12%
Recommended MC for long term storage
< or equal to 9%
Primary losses for drying
Spoilage, fungal damage, discoloration
Primary losses for milling
breakage
grain cracking
over-milling
Primary losses for storage
- Fungal, insect damage (grain storage)
* Loss of vigor (seed and long term storage)
Moisture content is determined by removing moisture and then measuring weight loss.
Direct method
measuring moisture using the
change in electrical or structural characteristic of a
material as a relationship of its moisture content
Indirect Method
methods such as biting,
shaking, and crunching are commonly used by both producers
and small traders.
Empirical Measurement
MC is determined with the use of
convection oven.
Air-oven Method
moisture is determined by fractional
distillation.
BROWN DUVEL Method
Moisture is determined by
evaporation using infrared
heaters as heat source.
Infrared method
This method measures the electrical properties (resistance and
capacitance) in relation to the moisture content in the grain.
Most commonly known in this method is the use of moisture
meters.
Secondary or Indirect method
measures how the material reduces the electrical
current flow. (value increases with moisture)
Resistance