Anti-digestion properties of amylosucrase modified waxy corn starch

Amylosucrase is a valuable enzymatic tool for the preparation of resistant starch (RS). This study investigated the morphology, thermal properties and molecular structure of the RS components resulting from the digestion of amylosucrase modified starches (MSs). Morphology of starch samples suggests that the surface of MSs is partially attacked by the digestion enzymes. Besides, the peak melting temperature of RSs shows a considerable increase compared with that of the corresponding MSs. Branch chain length distributions data reveals that the long branch chains of MSs are prone to being hydrolyzed, and the branch chains with degree polymerization of 22-32 are the largest populations among the RS components. Moreover, the RS content in MSs decreases significantly after thermal treatment. Overall results demonstrates that the existence of crystalline structure with thermostable double helices is responsible for the anti-digestion properties of modified starches.