Identification of the key structure, preparation conditions and properties of resistant dextrin for indigestibility based on simulated gastrointestinal conditions

Abstract

SummaryResistant dextrin has broad application prospects as a functional dietary fibre. However, the structural mechanism underlying indigestibility has not yet been reported. The structures and properties of three types of resistant dextrins before and after simulated digestion were characterised. The results showed that the new glycosidic linkages and α‐1,6 linkages dense distribution region were the main causes of resistance to digestive enzymes. Moreover, after the ordered crystal structure was damaged, new glycosidic linkages and 1,6‐anhydro‐β‐d‐glucopyranose were concentrated on the short side chain, which was not conducive to the formation of double‐helix structure, and the degree of branching (DB) increased. Thus, DB increased and negatively correlated with the degree of polymerisation and the average chain length. After adding transglycosidase, the dietary fibre content was higher than 70% and DB increased to 48.87%, indicating the strongest resistance to digestive enzymes. This study provides important information to produce resistant dextrin of higher indigestibility.