Moisture Analysis Flashcards
Moisture in materials refers to
all constituents that evaporate when the sample is heated, thereby leading to weight loss
Constituents include in moisture in materials
Water
Oil/Fat
Alcohol
Flavorings
Decomposition Products
Free Water
Water retains its physical properties acts ad dispersing agent
Adsorbed Water
Water that is attached to the surface of molecules like polysaccharides and proteins
Bound Water
Water that is physically trapped within crystals, such as crystalline starch, or other substances in food
Moisture can affect what
Perishability
Shelf-life
Physical/Chemical properties
Texture/flavor/etc.
Price
Thermogravimetry
the method used for extracting moisture from a sample by heating and determining the resulting loss of weight using a balance/scale
For effective drying air should be
Hot, dry and moving
Calculations for %Moisture
initial weight - final weight/ initial weight * 100
Sources of Error (Moisture Analysis)
Particle size
Volatile compounds present
Lipid Oxidation
Splattering
Improper storage
etc.
Total Solid
A measure of the amount of material remaining after all the water has been evaporated
Calculations for total solid%
% total solids = m dried/m initial * 100
% total solids = 100 - % moisture
Drying Methods Techniques
- Evaporation (Oven drying etc.)
- Distillation
- Chemical (Karl-Fisher Titration)
Types of Ovens
Forced Draft Oven
Vacuum Oven
Convection Oven
Microwave Drying Oven
Rapid Moisture Analyzer