The leafy spices are highly perishable in nature and therefore
have very short shelf life. Usually, they deteriorate rapidly after
harvesting which leads to loss of flavour and quality. So, there is
a need to preserve the product quality and also to prevent the
spoilage of the product during storage with an application of
drying technology. Food drying is a traditional way of food
preservation, and it has also been used for the production of
special foods and food ingredients 5. The term drying always refers
to the removal of a relatively small amount of moisture from a solid
or nearly solid material by evaporation 6, which promises microbial
stability and guarantees longer expected shelf-life of the product7.
Most of the drying methods used application of heat on the
products to remove moisture. Moreover, good drying technique
can enhance the quality of the product significantly 8. However,
different drying conditions and techniques can create diverse
food structure 9, 10. Previous studies revealed that numerous
methods of drying have been applied to food materials, especially
herbs and spices. Hot air drying is still the most widely used
method to produce dried products, because of their lower cost. In
addition, air drying of aromatic herbs can be an effective method
of preservation that inhibits growth of microorganism and delays
some biochemical reactions in the final product