Two different studies examined the effects of freezing and drying on potato and maize starch granules. Szymonska and Krok (2003) and Szymonska and Wodnicka (2005) discovered that freezing and thawing potato starch granules with 13% moisture caused erosion on the surface of the granules, resulting in an increase in specific surface area, total micro- and mesopore volume, and mean pore diameter. This change was not observed in maize starch granules.
Meanwhile, Zhang et al. (2014a) found that freeze-drying had different effects on the two types of starch granules. They reported that freeze-drying increased the susceptibility of potato starch granules (which have no surface pores and channels for enzyme access) to amylase, but did not have the same effect on maize starch granules (which do have surface pores and channels). Freeze-drying also caused surface damage to potato starch granules and reduced both short- and long-range molecular order of potato starch granular amylopectin more than that of maize starch granular amylopectin. These differences suggest that the effect of freeze-drying is dependent on the type of starch granule. The researchers suggested that the low temperature of freeze-drying caused greater chain rigidity and structural reorganization during water removal from B-type starch, as compared to oven drying.