Structural and Functional Characterization of Resistant Dextrins Prepared by Debranching and Recrystallization Methods

The purpose of this study was to investigate the structural and functional properties of resistant dextrins prepared by debranching and recrystallization. In this study, waxy maize and normal maize starches were used as raw materials to prepare resistant dextrins by debranching and recrystallization method. The morphological characteristics, crystalline structure, thermodynamic properties, functional groups and glycosidic bonds of the resistant dextrins were characterized, and their anti-digestive properties were explored. The results showed that compared with the native starch, the thermal stability and solubility of the two resistant dextrins were significantly increased (P<0.05), and had good color. The two resistant dextrins were rough in shape and showed small irregularly shaped fragmented aggregates. Waxy maize resistant dextrin showed a typical A-type crystalline structure and normal maize resistant dextrin showed a typical B-type crystalline structure. From the NMR spectra and infrared results, it could be seen that the glycosidic bonds of the resistant dextrins were broken and re-polymerized to form new anti-digestive glycosidic bonds during the preparation process, and there were no new functional groups generated. The anti-digestive ability of the two resistant dextrins increased, and the resistant dextrin prepared from normal maize starch had the strongest slowly digestible and anti-digestive ability. In conclusion, the debranching and recrystallization method can improve the anti-digestive ability of resistant dextrin, which will provide new ideas and theoretical guidance for the green preparation process of resistant dextrin and then realize the industrial production.