Revealing the Role of Self-Assembly Behavior of High-Assembly-Index Nano Amylopectin Ternary Complexes in the Slow Digestion Mechanism

Starch complexes have recently been identified as a new dietary supplement for dietary intervention in glycemic metabolism disorders. However, although the amylopectin significantly influenced starch complexes' anti-digestibility, the underlying regulatory pattern remains unclear. Accordingly, this study constructed nano white waxy maize amylopectin (WMA) ternary complexes with a high self-assembly index (SI, 82.58%) using an ultrasound-assisted approach. And the relationship between self-assembly behavior and slow digestibility was revealed. Combined analyses of chemometrics revealed that during the WMA ternary self-assembly process, the increasing free side chains and α-1,6 glycosidic linkages contributed to the rise in potential, thereby generating more assembly sites and binding energy and ultimately elevating SI. Then, along with the transition from a diffuse state to V_h-type crystallinity and spherical configuration, increases in relative crystallinity, double helices, molecular weight, short-range order, and gel-network viscous were observed, whereas semicrystalline lamellar thickness and "blocklet" size decreased. These indicated that both the number and dimensions of hydrolysis channels were reduced. Consequently, the increasing gelatinization temperature led to rising slowly digestible starch content (19.86-43.28%), causing a more stable glycemic release after WMA ternary self-assembly. This investigation provides a key theoretical and technological foundation for the development of novel slow-digesting precision nutrition ingredients.