Handbook of Size Exclusion Chromatography and Related ...

In the native environment (plant cell), starch granules are hydrated, and thus
in a swollen status. In first order, these conditions match with industrially hydrated
starch granules: in both cases the granules show up with increased order
(birefringence) and reduced hilum opening. In such swollen granules lcb-glucans
(amylose) diffuse out of amorphous regions, and, simultaneously, enable transfer
ionic compounds into and out of the granules. Chemistry-supported extraction
procedures (leaching) and drying result in the formation of compact granules with
cracked hilum.
3 ISOLATION/PURIFICATION OF GLUCANS FROM
STARCH RAW MATERIALS
Systematic analysis of technological qualities of starch materials includes different
levels of information: environmental and biological conditions, granule properties,
and molecular characteristics (Fig. 5).
Isolation of starch granules from native plant materials includes
pulverization and milling of starch-containing parts and subsequent separation
of granules from sliced cells with water. A sequence of repeated sieving and
washing concludes this first step. In industrial isolation processes, due to
technological limitations, an additional level of mechanical, thermal, and chemical
stress on the granules cannot generally be avoided. However, the granule status
after initial purification strongly controls “starch quality” for subsequent
processes.
Isolation of cereal starch granules for analytical purposes includes
elimination of adsorbed proteins (gluten), which may, for example, be achieved
Figure 5 Interdependencies of controlling influences for starch glucan properties.
© 2004 by Marcel Dekker, Inc.