Effects of molecular interactions in debranched high amylose starch on digestibility and hydrogel properties

Abstract In this work, the molecular entanglement, hydrogel properties, water mobility, and digestibility of debranched high amylose starch (DBHAS) with different debranching degrees were investigated to reveal the effects of molecular interactions on their digestibility and hydrogel properties. The results showed that the entanglement concentration and molecular entanglement strength decreased after debranching modification, indicating that hydrogels can be easily formed in DBHASes at lower concentrations and that the molecular interaction between amylose and linear short amylose is weaker than that between amylose and amylopectin. The high amylose starch hydrogel was unstable, and more free water exuded from the hydrogel. In contrast, more weakly and strongly bound water were held in the gel network and crystal structure of the DBHASes with higher debranching degrees, thus increasing their resistant starch fractions. These results confirmed that DBHAS has great potential in preparing stable hydrogels as low-glycemic gelling and clouding ingredients in the food industry.