The morphology of sericin powders was studied
using a scanning electron microscope. As can be seen
from the micrographs (Fig. 5), the particle shape
found to be very different in the two cases. The
standard sample is found to be made up of long
planar size particles, the test sample has spherical
globules. Another significant observation is that the
spherical globules have a very wide size distribution
and appear to be highly aggregated. Such particles
generally have problems with solubility. To study if
the particle shape is indeed characteristic of a drying
technique, another test was conducted where the
extracted liquor was freeze dried instead of spray
drying. The SEM of the powder obtained by freeze
drying is given in Fig. 5(c).
Planar shaped particles are obtained indicating that
particle shape is a function of the method of drying.
All other properties of the new powder are found
similar to the globular particles.