Normally in the intact starch granule, water enters into only amorphous zone. When starch
granule is damaged, crystalline regions are disrupted and water can to access to the whole
granule, allowing hydrogen bonding between water and exposed hydroxyl groups on
starches molecules. In addition, amylopectin was found broken down into low molecular
weight in the damaged starch but amylose is much less affected by physical impact (Han, et al., 2002). When starch is hydrated in cold water, damaged starch granules swell
spontaneously, lose birefringence, and give a translucent gel, while a few changes can be
observed in intact granule (Ever and Stevens, 1985).
Figure