Molecular structure and properties of cassava-based resistant maltodextrins

In-depth molecular structure and properties of cassava-derived resistant maltodextrins (RMDs) were determined. Cassava starch was dextrinized with 0.04% or 0.06% HCl at 120 degrees C for 60-180 min to obtain resistant dextrins (RDs), which were further hydrolyzed by alpha-amylase to produce RMDs. Prolonging dextrinization duration decreased proportion of alpha-1,4 linkages and alpha-/beta-reducing ends but increased fraction of indigestible alpha-/beta-1,6, beta-1,4, beta-1,2 linkages, degree of branching (DB), degree of polymerization, relative molecular weight, and total dietary fiber (TDF) content of the RMDs. Moreover, RMDs had greater proportion of beta-glycosidic linkages, alpha-/beta-reducing end, DB, TDF, and low molecular weight dietary fiber (LMWDF) content than their RD counterparts. Potential prebiotic activity score was higher in RMDs with abundant LMWDF fraction but low DB. Slight difference in the glass transition temperature of maximally freeze-concentrated unfrozen phase (T-g') and unfrozen water content was found among RMDs. However, RMDs had lower T-g' than their RD counterparts.