Freeze Drying is the process of removing the moisture from a biological
product while maintaining the Integrity of the products biological & chemical structure and activities. Freeze Drying
technology is used in particular for removal of moisture from the products usually of biological origin without causing any
noticeable change in the original characteristics. Freeze Drying is also the preferred process in the field of Pharmacy,
Chemistry and in conservation of food.
ADVANTAGE OF FREEZE DRYER:-
Heat-sensitive biological materials
may be freeze-dried without affecting their potency. The dried materials may be stored for years at room temperature without
loss of their original characteristics.
The freeze-dried material may be transported and shipped in small
containers, and no provision is necessary for refrigeration en route.
Bacterial growth and enzyme action do not
take place in freeze-dried products. Proteins do not coagulate.
Oxidation of many materials such as hemoglobin and
vaccines is completely prevented when drying and sealing is done under high vacuum.
SAFE TEMPERATURE & DRYING TIMES
FOR
SELECTED MATERIALS
MATERIAL
|
SAFE TEMP |
CONDENSER
TEMP.ºC |
MILK
|
-5 |
-40 |
UREA
|
-7 |
-40 |
BLOOD PLAZMA
|
-10 TO -25 |
-40 |
SERUM
|
-25 |
-40 |
VACCINE
|
-30 TO -40 |
-50 |
HUMAN TISSUE
|
-30 TO -40 |
-50 |
VEGETABLE TISSUE |
-50 |
-70 |