SUNDRYING AND DEHYDRATION Flashcards
is one of the man’s oldest methods of food preservation.
It enables foods to be saved for future use
DRYING
Principles of Drying
Enzymatic changes are retarded;
The growth of microorganism is severely hampered
Microbes themselves lose water and are rendered inert or inactive.
Advantages of Drying:
- Ease of transportation due to its lightness and requires only small amount of storage space;
- Good substitutes for fresh foods;
- No waste;
- Can be kept even at ordinary room temperature
- Concentrated and easy to distribute;
- Not so costly and require only minimum labor and equipment.
Applied to food products that have been dried by artificial means under controlled temperature and humidity conditions.
DEHYDRATED
is applied to foods in which a large proportion of moisture has been removed regardless of the method used and with little manipulation of the prevailing drying condition.
Dried
The use of sun’s energy to heat air and is the method used in drying harvested farm products.
The most economical method of food preservation
SUN DRYING/ SOLAR DRYING
The method of drying that is applicable to fruits since they contain sugar and other solutes in dilute solution.
It works on the principle that water can be removed from a dilute solution contained within a semi-permeable membrane.
OSMOTIC DEHYDRATION
The moisture content of fish flesh ranges from
75-83% water
Commonly used technique of preservation. The open space along the sea is the drying area of the community.
SOLAR DRYING
is used ,this prevent the attack of insects and contamination from the environment.
solar cabinet
is applied to a wide range of species, from small fish like “dulong” anchovies and sardines to large Spanish mackerel ,deboned milk fish, and group.
Drying
are hanged in racks taking advantage of the strong air current that passes around the hanging fish fillets.
fish fillet
Benefits of sulfuring fruits:
- Prevents darkening and brown discoloration
- Conserve Vitamin C;
- Makes plant cell membrane more permeable to water which hasten the drying process;
- Acts as fumigant for insects.
Discolorations Darkening of foods due to enzyme actions.
Discoloration
The formation of a hard, horny and impermeable surface on the outer covering of the food due to high dry temperature and low humidity.
Casehardening
Irreversible color change associated with overheating. Also referred to as scorching or burning.
Browning/ heat damage
Irreversible loss of the characteristic flavor and odor of original fresh foods.
Loss of volatile constituants
Water evaporates from foods which makes the product unsatisfactory.
Loss of ability to rehydrate completely
Due to exposure to high temperature
Loss or destruction of nutrients Due to exposure to high temperature
