Effects of Annealing and Heat-Moisture Treatment on Structural Characterization and In Vitro Digestibility of Debranched Mung Bean Starch

Resistant starch type 3 (RS3) exhibits physiological benefits in regulating post-meal blood sugar levels and enhancing gut microbiota balance. In this study, mung bean starch was isolated and modified through debranching, annealing (ANN) and heat-moisture treatment (HMT). The multi-scale structures investigated by SEM, FT-IR, and XRD unveiled the formation of short-range ordered, helix, and crystalline structures. Notably, RS3 formed through debranching and HMT exhibited both a remarkably high RS content of 54.71% and a low estimated glycemic index (eGI) of 51.78. Statistical evaluation through correlation and stepwise regression analyses suggested that short-range molecular order was the primary factor associated with the resistance of RS3 to enzymatic hydrolysis, while the chain length of B-chains exerted secondary yet notable influences. This work provided novel insights into the interplay between processing methodologies, ordered molecular structures, and starch digestibility resistance.