1. Moisture. Moisture content is an important property of powder,
which is related to the drying efficiency. Moisture content of a microencapsulated
product plays an important role in determining its
flowability, stickiness and storage stability due to its effect on glass transition
and crystallization behavior [21]. Moisture content of jamun juice
powders varied from 3.22 to 4.18% (Table 4), which is sufficient to make
food powder microbiologically safe. The moisture content of the powders
increased with an increase in the inlet temperatures, which may
be the due to crust formation on the drop surface. During spray drying,
the drying of a drop takes place in two stages. In the first stage, most of
the drying occurs as a result of free moisture vaporization from the surface
of the droplet. In the second stage, drying rate is lowered as a result
of crust formation at the drop surface and the concentration of unbound
water to the inner part of the droplet [22]. Especially for sugar-rich
products, evaporation is controlled by moisture diffusion in the crust