Digestibility of retrograded starches with A- and B-type crystalline structures

This study investigated whether the crystalline structure of the retrograded starch affects the contents of slowly digestible starch (SDS) and resistant starch (RS). When the relative crystallinities were similar, there was no difference in RS content between the retrograded starches with A- and B-type crystallites. However, the SDS content in A-type crystalline structure was constantly higher than B-type, contradicting the observation that the granular starches with B-type crystallites were more enzyme resistant. Therefore, the primary factor that accounts for the digestibility of granular starch is not the crystalline structure, but the granular properties, including the surface pores and the size.