2. INTRODUCTION
• Drying involves removal of water or another solvent by
evaporation from a solid, semi-solid or liquid by application of
heat and finally a liquid free solid product is obtained. In
general, drying is accomplished by thermal techniques but
non-thermal drying processes such as squeezing wetted
sponge, adsorption by desiccant (desiccation) and extraction
are also used. In bioproducts like food, grains, and
pharmaceuticals like vaccines, the solvent to be removed is
almost invariably water [1]
3. OBJECTIVE OF DRYING
• The main objectives of drying include to preserve foods and increase their
shelf life by
reducing the water content and water activity; avoid the need for use of
refrigeration systems for transport and storage (expensive); reduce space
requirements for storage and transport.
In pharmaceutical technology, drying is carried out for one or more of the
following
reasons: 1. To avoid or eliminate moisture which may lead to corrosion and
decrease the
product or drug stability. 2. To improve or keep the good properties of a
material like
![INTRODUCTION
• Drying involves removal of water or another solvent by
evaporation from a solid, semi-solid or liquid by application of
heat and finally a liquid free solid product is obtained. In
general, drying is accomplished by thermal techniques but
non-thermal drying processes such as squeezing wetted
sponge, adsorption by desiccant (desiccation) and extraction
are also used. In bioproducts like food, grains, and
pharmaceuticals like vaccines, the solvent to be removed is
almost invariably water [1]](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)